bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibiotic Stewardship Attitudes and Beliefs Among Frontline Staff Nurses: Impact of Virtual Education
Authors: Polisetty Radhika S. , Borkowski Jaime , Georges Dorothy , Mowers Stacy , Bolch Charlotte , Quiñones-Boex Ana , Murray Milena
Published: October 2022

Background: Nurses are vital healthcare team members and are often underutilised in antimicrobial stewardship (AS) activities. Several nursing responsibilities, such as taking allergy history and obtaining cultures, already overlap with AS activities. Nurses can play a crucial role in promoting AS in resource-limited settings. This study was conducted to assess frontline staff nurses’ baseline attitudes and beliefs towards AS, and see if a virtual education campaign consisting of newsletters and tip sheets would affect those attitudes and beliefs.

Methods: An online survey (pre-survey) was conducted of all in-patient nurses employed in the authors’ hospital on their attitudes and beliefs regarding AS. The survey consisted of 24 questions divided into three domains: demographic and practice information, nursing roles, and beliefs and attitudes towards AS programmes (ASP). After obtaining the results of the pre-survey, the authors started distributing monthly newsletters on various AS topics via email and posting them on a resource page. Topics included how to obtain an accurate allergy history, how to use microbiology results to help guide decisions, and stop therapy in cases of colonisation. The authors also distributed the same survey as a follow-up 6-month survey (post-survey) in March 2021 to gauge the impact of their virtual education efforts.

Results: In total, 109 nurses working in the adult in-patient setting of the authors’ institution completed the pre-survey in September 2020, and 64 nurses completed the post-survey in March 2021. Overall, most nurses had a positive attitude towards AS tasks, and over 90% of those who responded in the pre-survey and post-survey agreed with the statement that nurses are antibiotic stewards, thought it was important or very important to obtain appropriate cultures, and understood the relationship between Clostridioides difficile and antibiotics. Most pre-survey respondents listed knowledge gaps in microbiology (47 out of 64 [86%]) and antibiotics (53 out of 64 [84%]) as well as scope of practice concerns (48 out of 64 [75%]) as barriers to nurse participation. The virtual education helped raise the familiarity with the ASP and more nurses in the post-survey said they were familiar with the stewardship programme compared with the pre-survey (48.4% versus 23.2%; p=0.001).

Conclusions: This study showed that most nurses consider themselves antibiotic stewards and want to participate in AS activities; however, barriers to nursing involvement, such as lack of knowledge, scope of practice concerns, and time constraints, persist. Virtual education may be an option to increase nursing awareness and participation on ASPs in resource-limited settings.
Linguistic Theory intafsīrbetween 100/400 and 700/1000: Implications for Qur’anic Studies
Authors: Mårtensson Ulrika
Published: October 2022

The article aims to explore the possibility that tafsīr and the Qur’an might share a common linguistic theory, and the methodological relevance of such a relationship for Qur’anic studies. This is done by, firstly, engaging with debates on the definitions and dating of tafsīr and the methodological implications of these; secondly, by developing a model of a theoretical paradigm that spans the disciplines of tafsīr, linguistics, rhetoric, and law, and applying it to the interpretations of key terms in five Qur’anic verses as found in the works of a selection of exegetes. The exegetes in question are Muqātil b. Sulaymān (d. 150/767), ʿAbd al-Razzāq al-Ṣanʿānī (d. 211/827), Yaḥyā b. Sallām (d. 200/815), Ibn Abī Zamanīn (d. 399/1009), and al-Ṭabarī (d. 310/923). The case studies are Q. 1:5–7 ( mustaqīm); Q. 2:1 ( aliflāmmīm dhālika’l- kitāb); Q. 2:125 ( maqām Ibrāhīm); Q. 19:34 ( qawl al-ḥaqq); and Q. 18:19 ( azkā ṭaʿāman).

The analysis finds that (1) tafsīr shares a pragmatist semantic paradigm with linguistics and law, and the selected exegetes’ legal methodologies are decisive in shaping their exegetical methods; (2) studies of developments within tafsīr need to consider its relationship with the other disciplines and the diverse exegetical genres; and (3) the pragmatist semantic paradigm connects tafsīr methodology with the Qur’an’s composition and some of its concepts, because they reflect the same theory that meaning depends on context. Consequently, if tafsīr is studied from a discipline- and theory-oriented perspective, it can provide new methodologies for Qur’anic studies.
Argument Structures in Sūrat al-Nūr: A Pragmatic Approach
Authors: Khalil Hana
Published: October 2022

This study aims to employ the theory of ‘argument structures’ in the analysis of Sūrat al-Nūr, on the basis that rhetorical devices are a means of extracting the reasons and logical arguments that lead to a particular conclusion, while taking into account the status of the speaker, the addressee, and the purpose of the message. In particular, this theory addresses the following three aspects: (1) the descriptive aspect, which tracks the events and descriptions in the sura; (2) tracing the similes used in the sura as a means of revealing its message; (3) the use of coordinating conjunctions in expressing arguments, which is based on investigating conjunctions together with their functions. Furthermore, the study also analyses Sūrat al-Nūr at level of the context, through the connection made between the topics presented in this sura and the preceding and following suras. To achieve this, this study employs the pragmatic approach as a framework where the context is the basic source to interpret what is intended in the Qur’anic discourse.
The Effect of the Front Plate with Ribs on Brush Seal Flow Characteristics
Authors:   Dalian Maritime University, Yue Benzhuang , Liu* Yuxin ,   Dalian Maritime University, Kong Xiaozhi ,   Dalian Maritime University, Chen Hua ,   Dalian Maritime University, Lu Huawei ,   Dalian Maritime University
Published: October 2022

In highly inlet swirling environment, the bristles of brush seal tend to circumferentially slip, which may lead to aerodynamic instability and seal failure. In this paper, a new structure of front plate with ribs was designed to reduce the influence of high inlet swirl on bristle pack, and a three-dimensional porous medium model was used to simulate the brush seal flow characteristics. The effects of the geometric parameters of ribs, including inclined angle (-20º-40º), spacing (5mm-15mm) and height (0.5mm-1.5mm) on the pressure and flow fields as well as the leakage behavior were investigated. Results show that the ribs structure can effectively regulate and control the upstream flow pattern of the bristle pack, inducing the swirl flow into radially inward, which results in decreased circumferential velocity component. The ribs with inclined angle of 20 degree, height of 2mm and spacing of 5mm were observed to have the best effect on reducing inlet swirl and improving the brush seal stability.
Study on the Flow Characteristics of Fan Coupled Nacelle Intake under Different Angle of Attack
Authors:   Northwestern Polytechnical University, Qi Min , Wang Zhanxue ,   Northwestern Polytechnical University, Zhou Li ,   Northwestern Polytechnical University, Deng Wenjian ,   Northwestern Polytechnical University
Published: October 2022

The main function of nacelle intake is to provide the fan with stable and uniform flow in a wide operating range. The next-generation civil turbofan engine requires nacelle intake to have shorter length and larger lip thickness. However, the thicker lip is, the higher the probability flow to be separated, and the total pressure distortion disturbance is quickly transmitted to the fan, which causes the increase of the inhalation of distortion. Eventually, the stability of the engine is destroyed. Therefore, it is necessary to study the distortion of the nacelle intake and the coupling effect of the nacelle intake and fan. Aiming at the coupling effect of intake distortion of the nacelle intake and fan under a high angle of attack, the research focus on the flow characteristics of isolated nacelle intake and intake/ fan integrated model under different angle of attack. Results show that the intake presents different flow patterns under different Ma and mass flow rate; however, the interaction between the intake and fan presents a similar pattern. The presence of fan leads to the flow swirl angle changes significantly and mass redistribution. The studies also indicate that the intake distortion sensitivity level decrease with the fan coupling. The sensitivity of the distortion index decreases from 4.057% to 0.315% under cruise condition; the sensitivity of the distortion index decreases from 0.186% to 0.1423% under take-off condition.
EFFECT OF SURFACE TENSION CORRECTION COEFFICIENT ON NON-EQUILIBRIUM CONDENSATION FLOW OF WET STEAM
Authors:   Department of Power Engineering, North China Electric Power University, Yao Bochuan , Han* Xu ,   Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Yuan Yunyun ,   Department of Power Engineering, North China Electric Power University, Han Zhonghe ,   Department of Power Engineering, North China Electric Power University
Published: October 2022

In view of the non-equilibrium characteristics of water vapor in the condensation process, there are deviations in the prediction of condensation process by various models. The surface tension of water droplets appears in the exponen-tial term of nucleation rate in the form of third power, which has a significant impact on the distribution of parameters such as condensation location, number of water droplets and steam wetness. The correction coefficient was used to modify the plane surface tension calculation model. The non-equilibrium condensation process in the Moses&Stein nozzle was simu-lated. By comparing with the experimental data, the influence of the surface tension correction coefficient on the calculation accuracy of the model was analysed. And the functional relationship between the inlet subcooling and the optimal surface tension correction coefficient was further obtained. Taking case 252 as an example, with the surface tension correction coefficient increasing from 0.9 to 1.05, the condensation position moves from 3.1cm to 4.2cm, and the optimal correction coefficient is 0.98. There is a significant positive correlation between the optimal tension correction coefficient and inlet subcooling under different working conditions. The results can provide a reference for the calculation of wet steam con-densation flow.
EFFECTS OF GEOMETRIC AND OPERATIONAL UNCERTAINTIES ON THE AERODYNAMIC PERFORMANCE OF A CENTRIFUGAL COMPRESSOR STAGE
Authors:   Xi’an Jiaotong University, Rui Zhu Rui Zhu , Yaping Ju Yaping Ju ,   Xi’an Jiaotong University, Chuhua Zhang Chuhua Zhang ,   Xi’an Jiaotong University
Published: October 2022

No real centrifugal compressor performance exactly conforms to its design geometry and expected operating conditions due to the uncertainties existing in the manufacturing and in-service process. The compressor performance can be adversely affected by such uncertainties and performs instability. However, relevant studies concerning geometric and operational uncertainties simultaneously are quite rare, and the underlying flow mechanism even remains unknown. Here we present both deterministic and uncertainty analysis of a centrifugal compressor stage with considering geometric and operational uncertainties simultaneously. With the combination of CFD simulation and nonintrusive sparse grid based stochastic collocation methods, the combined and single effects of total inlet temperature, total inlet pressure, outlet mass flow, impeller tip clearance and hub fillet radius on the stage/impeller performance are quantified and analysed. The results show that these uncertainties exert more influence on stage rather than impeller performance, therein the uncertain tip clearance contributes the most. To investigate such declined performance indeed, the flow field was then uncovered. It is demonstrated that the wake of tip clearance produces distorted flow downstream towards the diffuser, which causes complicated vortex structures. This present study lays a theoretical foundation to provide guidelines for developing a robust design of centrifugal compressor.
NUMERICAL SIMULATION ON INTERNAL FLOW AND HEAT TRANSFER OF SWEEPING JET AND FILM COMPOSITE COOLING ON A FLAT PLATE
Authors:   Institute of Engineering Thermophysics, Chinese Academy of Sciences North China Electric Power University, Kong Xiangcan , Zhang Ziqing ,   Institute of Engineering Thermophysics, Chinese Academy of Sciences University of Chinese Academy of Sciences, Li Guoqing ,   Institute of Engineering Thermophysics, Chinese Academy of Sciences University of Chinese Academy of Sciences, Zhang Yanfeng ,   Institute of Engineering Thermophysics, Chinese Academy of Sciences University of Chinese Academy of Sciences
Published: October 2022

Numerical simulation has been performed to investigate the internal heat transfer characteristics of sweeping jet and film cooling together with the representative flow characteristics on a flat plate. SST k_-_ω _turbulence model was employed for a fluidic oscillator with twenty cylindrical film holes at four different blowing ratios and four different inclination angles. Time-resolved flow fields and time-averaged heat transfer analysis considering thermal convection and conduction by coupling of fluid and solid domains were presented. Results indicate that the total pressure loss coefficient of sweeping jet is larger than those of normal jet, especially when blowing ratio is relatively higher. The Nu number monotonously increases with the increase of blowing ratio and decrease of inclination angle in all different cases, but the Nu number distribution on the impingement wall is insensitive to the inclination angle of film holes. Compared to normal jet, sweeping jet has a more spatially uniform heat removal rate, but the area-averaged Nu number is higher only when blowing ratio is 4. Therefore, sweeping jet and film composite cooling is desirable to make the distribution of flat wall heat transfer more uniform, but the impinge distance of fluidic oscillator should be further optimized to improve the impingement cooling effectiveness and the total pressure loss coefficient.
EFFECT OF LEADING-EDGE/TRAILING-EDGE GEOMETRY ON UNCERTAINTY AERODYNAMIC PERFORMANCE OF A 2D LOWPRESSURE TURBINE BLADE
Authors:   National Key Laboratory of Science and Technology on Aero-Engine Aerothermodynamics, School of Energy and Power Engineering, Beihang University, Wang Xiaojing , Zou Zhengping ,   1. National Key Laboratory of Science and Technology on Aero-Engine Aerothermodynamics, School of Energy and Power Engineering, Beihang University 2. Research Institute of Aero-Engine, Beihang
Published: October 2022

Inevitable geometric variations in manufacturing process will lead to variations of aerodynamic performance of turbine blades, and uncertainty design considering this influence is significant for the robustness of the actual performance. In this paper, the uncertainty aerodynamic performance, which considers the influence of the same geometric variations, under different design conditions of leading-edge/trailing-edge geometry was compared and analysed in detail. The results showed that the actual performance is mainly affected by the leading-edge geometry, and the influence of trailing-edge geometry is relatively small. The design value and mean value of total pressure loss are mainly negatively affected by the short radius and the wedge angle of leading-edge ellipse, and positively affected by the radius of trailing edge, respectively. Similarly, the standard deviation of total pressure loss is mainly negatively affected by the short radius and the wedge angle, and positively affected by the long/short radius ratio of leading-edge ellipse, respectively. Detailed analysis explained the mechanisms, and the guidance for the corresponding uncertainty design was derived.
LARGE EDDY SIMULATION OF CORNER STALL CONTROL IN A LINEAR COMPRESSOR CASCADE BY BLENDED BLADE AND ENDWALL TECHNIQUE
Authors:   Beijing Institute of Technology, Zhu Huiling , Zhou Ling ,   Beijing Institute of Technology, Li Jiabin ,   Tsinghua University, Meng Tongtong ,   Beijing Institute of Technology, Ji Lucheng ,   Tsinghua University
Published: October 2022

Under the influence of a strong adverse pressure gradient, secondary flow, and other factors, compressor cascades are prone to corner separation, and even leading to corner stall, which seriously affects aerodynamic performance. In this paper, large eddy simulation is used to investigate the effects and mechanisms of corner stall controlled by the blended blade and endwall technique. The suction side root of a modified NACA65 blade is designed by this technique. The results show that the corner stall topology is changed, in which a single large separation vortex on the endwall is weakened and broken into two small separation vortices, and the spanwise and pitchwise ranges of corner separation are reduced. Most importantly, the total pressure loss coefficient is reduced compared with the prototype cascade. All above prove that the blened blade and endwall technique can control corner stall in the compressor cascade to a certain extent. The underlying physical mechanisms are as follows: by increasing the dihedral angle, the intersection of the boundary layers and the development of the corner vortex are obviously suppressed. Moreover, the axial and spanwise forces generated by the technique can increase the kinetic energy of the surrounding fluid and transport the low-energy fluid upward to reduce accumulation on the endwall respectively.
STRUCTURAL OPTIMIZATION OF THE WING BOX FOR A HYBRID-ELECTRIC COMMUTER AIRCRAFT
Authors:   Aristotle University of Thessaloniki, Nasoulis Christos P. , Tsirikoglou Panagiotis ,   Limmat Scientific AG, Kalfas Anestis I. ,   Aristotle University of Thessaloniki
Published: October 2022

Hybrid-electric commuter aircraft segment is playing a significant role in the electrification of air transportation. Towards the achievement of efficient and robust transportation, design and optimization processes are necessary to evaluate the different aircraft components. Within this context, the current work investigates the impact of the positioning of the propulsion system and spars on the structural integrity of a hybrid-electric commuter aircraft. The proposed approach is based on an in-house aircraft sizing tool, along with geometry generation and high-fidelity structural evaluation models. These tools are tailored in an automated computational pipeline, that includes pre-processing, model evaluation and postprocessing tasks, able to perform design space exploration and optimization over different loading conditions of a selected mission envelope. This work focuses on the assessment of the impact of the additional non-structural weight e.g., batteries, fuel, and propulsion components, inside the wing box, on the stress, deformation and spanwise thickness distribution of the structure. The effect of spars and propulsion system positioning on the available storage space, maximum stress and displacement is discussed, with the aft spar having the greatest impact. Finally, the structural model is optimized to minimize the mass, resulting in a 29 % weight reduction, compared to the initial design.
Effects of streamwise vortices on the film cooling effectiveness of a fanshaped hole
Authors:   University of Shanghai for Science and Technology, Cui Xiao-feng , Ren Dai ,   University of Shanghai for Science and Technology, Liu Peng-min ,   University of Shanghai for Science and Technology, Lin Chi-xiang ,   University of Shanghai for Science and Technology
Published: October 2022

Fan-shaped hole is a typical shaped hole frequently used in gas turbine film cooling, which may operate in a complex vortical flow environment of turbine blade rows. A vortex generator (VG) was installed in front of a single row of fan-shaped holes to produce streamwise vortex on a flate plate to simulate the vortical flows environment of the gas turbine. Effects of streamwise vortices on the film cooling effectiveness of a discrete fan-shaped hole were experimentally studied. Results show that streamwise vortices intensify the mixing of mainstream and coolant jet, the film cooling effectiveness decrease sharply, the maximum reduction of the area-averaged-film cooling effectiveness is 63%. At the high blowing ratio M=2.5, streamwise vortices can restrain lift-off tendency of the coolant jet and retard the decrease of film cooling effectiveness. Also of importance are the changes of the film cooling distributions and coverage area, which occur as the lateral position of the vortex is changed.
PARAMETRIC ANALYSIS OF THE SHEAR LAG EFFECT IN SERPENTINE NOZZLES UNDER FLUID-THERMAL-SOLID COUPLING INFLUENCE
Authors:   Northwestern Polytechnical University, Huang Sheng , Rong Le ,   Northwestern Polytechnical University
Published: October 2022

The serpentine nozzle is subjected to high temperature gas pipe flow and concentrated loads. As a thin-walled structure, the rectangular straight section is the region with the most severe local deformation and the most obvious shear lag. In this paper, the shear lag effect in the serpentine nozzle will be observed and analyzed on a series of fluid-thermal-solid coupling numerical models. A parametric analysis will be conducted with structural variations, for the purpose of giving recommendations for an optimal design of a serpentine nozzle.
MULTI TRAVELING WAVE FLUTTER ONSET IN TUNED BLADED-DISKS
Authors:   Universidad Politécnica de Madrid, Javier González-Monge Javier González-Monge , Salvador Rodríguez-Blanco Salvador Rodríguez-Blanco ,   Universidad Politécnica de Madrid, Carlos Martel Carlos Martel ,   Universidad Politécnica de Madrid
Published: October 2022

Flutter is a major constraint on modern turbomachines; as the designs move toward more slender, thinner, and loaded blades, they become more prone to experience high cycle fatigue problems. Dry friction, present at the root attachment for cantilever configurations, is one of the main sources of energy dissipation. It saturates the flutter instability growth producing a limit cycle oscillation whose amplitude depends on the balance between the energy injected and dissipated by the system. Since both phenomena, flutter and friction, are small corrections of the elastic behavior of the structure, it takes many elastic oscillations for them to manifest and modulate the oscillation amplitude. Furthermore, even longer time scales appear when multiple traveling waves are aerodynamically unstable and exhibit similar growth rates, with a very slow energy transfer rate between them. All these slow scales make the system time integration very stiff and CPU expensive, bringing some doubts about whether the final solutions are properly converged. In order to avoid these uncertainties, a numerical continuation procedure is applied to analyze the solutions that set in, their traveling wave content, their bifurcations and their stability. The system is modeled using an asymptotic ROM and the continuation results are validated against direct time integrations. New final states with multiple traveling wave content are found and analyzed. These solutions have not been obtained before for the case of microslip friction at the blade attachment; only solutions consisting of a single traveling wave have been reported in previous works.
Experimental Study on Overall Cooling Effectiveness of Three-layer Laminate for Stealth Aircraft Tail Boom
Authors:   School of Power and Energy, Northwestern Polytechnical University, Cao Feifei , Ma Zhao ,   AECC, Liu Cun Liang ,   School of Power and Energy, Northwestern Polytechnical University, Dong Chao ,   School of Power and Energy, Northwestern Polytechnical University, Zhou Tian Liang ,   School of Power and Energy, Northwestern Polytechnical University
Published: October 2022

To study the cooling problem of stealth aircraft tail boom, which caused by the application of exhaust nozzle retraction technology. A Three-layer laminated cooling structure was established for tail boom. The overall cooling effectiveness and discharge coefficient of the structure were experimentally measured with different impingement distances (Hi/Dih=0.83,1.39) under blowing ratios (M=0.075~0.375), based on the infrared temperature measurement technology. The experimental results indicate that the laminated structure designed in this paper can efficiently cool the hot side wall of the tail boom for stealth aircraft. The area-averaged overall cooling effectiveness is 0.55~0.81 in the range of BR=0.075~0.375. The optimum blowing ratio is 0.300, and the corresponding area-averaged overall cooling effectiveness is above 0.8. The impingement distance has little effect on the overall cooling effectiveness. Hi/Dih increases from 0.83 to 1.39, the peak value of laterally averaged cooling effectiveness decreases, and the cooling uniformity of laminate surface is improved. Increasing the impingement distance will significantly reduce the flow resistance of this laminate. However, the flow resistance of three-layer laminate is still relatively large, Cd=0.098 for Hi/dfh=0.83 and Cd=0.132 for Hi/dfh=1.39. The flow resistance performance of this new structure needs to be studied to improve.
Influence of shield on supersonic inlet characteristics
Authors:   School of Power and Energy, Northwestern Polytechnical University, Cai Feichao , Huang Xing ,   AECC HUNAN AVIATION POWERPLANT RESEARCH INSTITUTE
Published: October 2022

For the supersonic inlet with shield plate, the internal and external flow integration calculation model is established. The influence of shield plate on the flow field parameter distribution of the supersonic inlet is studied by numerical method. The influence of shield plate length on the flow field and inlet performance is analyzed. The influence of shield plate on the aerodynamic performance of the body / inlet with abdominal layout is studied by comparing with the scheme without shield plate The influence of interference. The simulation results show that the shield plate can adjust the shock system configuration of the supersonic inlet and improve the angle of attack characteristics of the inlet. The length of the shield plate has a significant effect on the pre compression effect of the inlet air flow. Adding the shield plate can reduce the interference of the body on the inlet flow field.
Compressor Tandem Cascade Flow Prediction by Adaptive POD-RBFN Reduced Order Model
Authors:   1. Yangtze River Delta Research Institute 2. Northwestern Polytechnical University, Shang Xun , Liu Hanru ,   1. Yangtze River Delta Research Institute 2. Northwestern Polytechnical University, Du Yican ,   Northwestern Polytechnical University, Hu Zhijie ,   Northwestern Polytechnical University
Published: October 2022

The tandem cascade of compressor can perform larger flow turning angle and less losses than a single-row cascade. The Proper Orthogonal Decomposition (POD) was used in this paper to extract the dominant mode of the tandem flow field especially the gap injection between two blades. Radial Basis Function Network (RBFN) was used to respond to the coefficients of POD basis function for one Reduced-order-model (ROM) construction, so as to predict the flow field. It is concluded that the combined method can be utilized to accurately predict the aerodynamics parameters and flow field of tandem cascade. The adaptive sampling method was developed to further advance the sampling efficiency for ROM prediction. The result shows that the adaptive sampling method has obvious advantages compared with static sampling in terms of efficiency and accuracy.
Non-Intrusive Flow distortion measurements within a Turbofan Intake (NIFTI)- De-risking the test campaigns with CFD analysis
Authors:   Imperial College Lodnon, Zhang W. , Tiedemann B. ,   Imperial College Lodnon, Hegen S. ,   German-Dutch Wind Tunnel, Vahdati Mehdi ,   Imperial College London, Zachos Pavlos ,   Cranfield University, Zhao F. ,   Imperial College London
Published: October 2022

Short and slim aero-engine intake designs for very high bypass ratio configurations cause notable levels of steady and unsteady distortions at the fan face, especially under crosswind or AOA operation during aircraft take-off. Such distortions can adversely affect the engine’s performance, operability, structural integrity and safety margin with potentially catastrophic consequences for the entire propulsion system. There is a significant lack of open published measured data for fans and compressors operating under inlet distortions, which is mainly due to the difficulties and cost involved in setting up such experimental campaigns. The Non-Intrusive Flow distortion measurements within a Turbofan Intake (NIFTI) project aims to address this gap by demonstrating a non-intrusive technique for measuring velocity fields across a plane located upstream of a large diameter fan of a high bypass ratio aero-engine which has never been achieved. This method will provide synchronous datasets across the measurement plane with at least one order of magnitude higher spatial resolution than current methods. The experimental activities will be supported by numerical campaigns and advanced data processing of measured data, which will be used to analyse the highly unsteady nature of the flow distortions. The outcome of this project will ultimately unlock the complex aerodynamics of closely coupled fan-intake systems and aid the validation of CFD codes, as well as establish novel design guidelines for future, stall-tolerant aero-engines. This paper reports on the initial finding from CFD analysis of NIFTI project, focusing on the investigation of the interaction between the distortion caused by the AOA (upstream) and pylon (downstream) on a low-speed fan blade operation and addressing the possible aerodynamic instabilities which can arise for such a system. The aim is to use CFD to predict aerodynamic and in-future aeroelastic stability of the coupled fan-intake configuration prior to the test campaigns in order to computationally determine the operating envelope of the rotating fan experimental facility.
INVESTIGATION OF STAGGERED LABYRINTH TIP SHROUD ON FLOW MECHANISM OF LOW-PRESSURE TURBINE
Authors:   Institute of Engineering Thermophysics, Chinese Academy of Sciences University of Chinese Academy of Sciences Innovation Academy for Light-duty Gas Turbine, Chinese Academy of Sciences, Tan Wei , Zhang Ziqing ,   Institute of Engineering Thermophysics, Chinese Academy of Sciences University of Chinese Academy of Sciences Innovation Academy for Light-duty Gas Turbine, Chinese Academy of Sciences, Qu Xiao ,   Institute of Engineering Thermophysics, Chinese Academy of Sciences University of Chinese Academy of Sciences Innovation Academy for Lightduty Gas Turbine, Chinese Academy of Sciences, Li Lin ,   Institute of Engineering Thermophysics, Chinese Academy of Sciences University of Chinese Academy of Sciences Innovation Academy for Lightduty Gas Turbine, Chinese Academy of Sciences, Zhang Yanfeng ,   Institute of Engineering Thermophysics, Chinese Academy of Sciences University of Chinese Academy of Sciences Innovation Academy for Lightduty Gas Turbine, Chinese Academy of Sciences
Published: October 2022

In this paper, the unsteady simulations of shrouded low-pressure turbine with staggered and conventional labyrinth cavities is conducted for investigations of the improvement mechanism of labyrinth structures for aerodynamic performance. Current tip shroud cavity design principle is based on the total pressure loss propogational related to leakage fraction. Staggered labyrinth seal, however, reduces the total pressure loss more than the linearly evaluation. Static pressure ratio between each fin gap is reduced in staggered labyrinth seal configuration, thus reducing the input momentum in each sub-cavity devided by fins. Secondary eddies of cavity flow is controlled and oscillations of pressure wave propogation is strengthened by circumferential migration and reduced room in each sub-cavity, resulting in stable toroidal vortices and reduction of viscous loss. Strengthened interaction in shroud outlet gap and reduced leakage fraction lead to the blockage of leakage mass flow, thus controlling the secondary loss structure of mixing of leakage jet in main flow. Research in this paper provides a reference for reducing the difficulties in the overdesign for leakage related efficiency loss in turbine design, and offers the idea for evaluating the efficiency loss more properly.
High fidelity finite element model updating and deviation characterization method for geometric mistuned bladed disks
Authors:   Chongqing University, Liang Daosen , Zhang Rui ,   Chongqing University, Wu Yulin ,   Chongqing University, Jia Zichu ,   Chongqing University, Cao Zhifu ,   Chongqing University, Yao Jianyao ,   Chongqing University
Published: October 2022

To accurately obtain the influence of geometric deviation on the vibration characters of the bladed disk. It is necessary to count the deviation characteristics of a large number of real bladed disks and establish the highfidelity structural analysis model. An automatic finite element model updating method of mistuned blade disks and characterization method of blade geometric deviation is proposed in this paper. The geometric mistuning blade finite element model is obtained by moving the finite element structured mesh nodes to the measured point cloud data. The proposed finite element model updating method includes bladed disk cloud processing, blade surface classification, blade node movement. The method can be applied to large deformed blades and damaged blades. The obtained geometric deviation can accurately distinguish the abnormal blade model. The surface measurement data of the blade is obtained by a blue light optical scanner. Compare with the blade modal experiments result, the updated highfidelity finite element calculation result error was less than 8‰.
Hybrid location-allocation algorithm for large scale energy system planning: A case study of the hydrogen supply chain in Belgium
Authors:   Université catholique de Louvain, Davide Tonelli Davide Tonelli , Alessandro Parente Alessandro Parente ,   Université libre de Bruxelles, Francesco Contino Francesco Contino ,   Université catholique de Louvain
Published: October 2022

Renewable electricity-based fuels (electro-fuels) represent a necessary step to achieve the carbon neutrality by 2050. Hydrogen is the common feedstock of all electro-fuels and an annual production growth of 83% is required to satisfy the targets of national strategies by 2030. Yet, the cost of the hydrogen supply chain remains the main bottleneck for its rollout. We developed a framework to study the cost optimal infrastructure design for the production and dispatch of hydrogen to satisfy the locally distributed demand. With a granularity of 40 km 40 km the economy of scale has only a partial effect, leading to a limited reduction of the total cost of hydrogen production and distribution. The optimal system design is a hybrid configuration with concentrated production close to the highest demand point and distribution to the neighbouring cells. Future work will focus on refining the cost description, increase the granularity of the demand and extend the analysis to the main electro-fuels.
Quantification of Swirl Distortions Caused by S-shape Inlet Ducts
Authors:   School of Energy and Power Engineering, LI Zhenyu , DONG Xu ,   Research Institute of Aero-engine, SUN Dakun ,   School of Energy and Power Engineering, SUN Xiaofeng ,   School of Energy and Power Engineering
Published: October 2022

The S-shape inlet is generally the main reason for the occurrence of swirl inlet distortion that is seriously concerned by the manufactures of fighters. The non-uniform inlet combined with large-scale bulk swirl, small-scale tight-wound swirl, or both of them may greatly impact the performance of aero-engines. Focusing on the swirl patterns and the effects of swirl flow on the compression system, many attempts have been carried out. However, there is still no general and quantitative criterion for assessing the swirl pattern and intensity to serve the further performance or stability analysis. In this paper, a vorticity-based method was used to quantify the swirl inlet distortion caused by different S-inlet ducts. Three series of S-ducts with different offset distances and different lengths were designed. Numerical investigations on the intensity and form of swirl distortion were carried out to achieve quantitative results.
Numerical study on flow and heat transfer characteristics in an impingement/effusion cooling system with high blockage ribs
Authors:   Northwestern polytechnical university, Kong Dehai , Ma Zhenyuan ,   Northwestern polytechnical university, Isaev Sergey A. ,   Saint-Petersburg State University of Civil Aviation, Liu Cunliang ,   Northwestern polytechnical university
Published: October 2022

In this paper a numerical study is conducted to investigate the flow structure and heat transfer performance of jet impingement inside a narrow target channel with high blockage ratio transverse rib turbulators of different arrangements relative to effusion holes on the target wall, which represents a simplified system from mid-chord region of a turbine blade. The rib turbulators are transversely mounted between the locations of the impingement jet and effusion holes. The jet Reynolds number based on the injection hole diameter is 4,000, 8000 and 12,000, respectively. The effect of blockage ratio (e/DH =0.12 0.18 and 0.29) and rib arrangement (in front of or behind the effusion hole) on the flow structure, local and global average heat transfer characteristics in the impingement/effusion cooling systems are numerically investigated with Reynolds Averaged Navier–Stokes (RANS) method in detail. Furthermore, the calculated data on the rib roughened wall are also compared with those on the smooth wall for the impingement/effusion cooling system. Results show that the placement of ribs on the target wall produces a much greater heat transfer enhancement by up to 18%. The local heat transfer distributions and their uniformity are significantly affected by the position of rib turbulators. Moreover, the increase of rib blockage ratio is beneficial to increase the overall heat transfer level and thermal-hydraulic performance of impingement/effusion systems with ribs.
A NUMERICAL STUDY OF INFLUENCE OF INTERNAL CRACK ON THERMAL PROPERTY OF APS-TBCs
Authors:   School of Mechanical Engineering, Gas Turbine Research Institute, Shanghai Jiao Tong Univ., Yun Long Yun Long , Yuzhang Wang Yuzhang Wang ,   School of Mechanical Engineering, Gas Turbine Research Institute, Shanghai Jiao Tong Univ., Xiaohu Chen Xiaohu Chen ,   School of Mechanical Engineering, Gas Turbine Research Institute, Shanghai Jiao Tong Univ., Kanru Cheng Kanru Cheng ,   School of Mechanical Engineering, Gas Turbine Research Institute, Shanghai Jiao Tong Univ., Licheng Shi Licheng Shi ,   School of Mechanical Engineering, Gas Turbine Research Institute, Shanghai Jiao Tong Univ., Runxuan Sang Runxuan Sang ,   School of Mechanical Engineering, Gas Turbine Research Institute, Shanghai Jiao Tong Univ.
Published: October 2022

The internal crack initiation and propagation are decisive factors that dominates the failure of thermal barrier coatings under services. In this paper, TBCs samples with different crack lengths were numerically reconstructed. The temperature distribution characteristics of the surface and internal thermal barrier coatings were studied based on the coupled flow and heat transfer model of thermal barrier coatings and cooling film by using LBM-DDF method. The results show that the existence of cracks will greatly change the temperature distribution of the coating, resulting in increased temperature inhomogeneity and local sintering of the coating. This will lead to stress concentration, which can easily cause early delamination and fracture of the coating, thus affecting the durability of the coating. The results can provide a helpful reference for better technical support for life prediction of high temperature turbine blades.
LES PREDICTION OF TRANSITIONAL FLOWS IN LP TURBINE CASCADES: FLOW PHENOMENA AND EFFECTS OF NUMERICAL SETUP
Authors:   IHI Corporation, Tateishi Atsushi , Tani Naoki ,   IHI Corporation, Okamura Yasuhiro ,   IHI Corporation, Hamabe Masaaki ,   IHI Corporation
Published: October 2022

This paper presents detailed validations of a Large Eddy Simulation (LES) methodology for various transitional phenomena in low pressure turbines. The results are discussed to identify key phenomena to be resolved accurately toward future industrial use of LES. Detailed comparisons between experimental and CFD results are made on three different 2D cascades with different blade loading. One is low-lift and fully laminar design, while the others are moderate- and high-lift designs with boundary layer transition. The experimental data are obtained in a low speed linear cascade at Iwate University. All computations are conducted by a carefully-designed overset LES code. For the high-load design with a distinct laminar separation on the suction side, the LES result shows satisfactory agreement with the test. However, although the peak of total pressure loss distribution is predicted quite accurately, integrated cascade losses are overpredicted in the other two cases. For the laminar blade, the LES result implies some differences can exist in the state of wake, while the transitional blade shows delay of transition in the boundary layer. The effects of inflow turbulence intensity, length scale, and stream tube contraction are discussed in detail to improve LES prediction.
Numerical analysis on system performance of a pre-swirl air supply system about the improvement of receiver hole structure
Authors:   Northwestern Polytechnical University, Gong Wenbin , Liu Gaowen ,   Northwestern Polytechnical University, Lin Aqiang ,   Northwestern Polytechnical University, Wang Fei ,   Air-to-Air Missile Research Institute of China, Wang Zhiwu ,   Northwestern Polytechnical University
Published: October 2022

As an important component for a pre-swirl air supply system, the performance of the receiver hole directly affects the quality of cooling air supplied to turbine rotor blades of an aeroengine. For a high-radius pre-swirl system with a difference in radius between the pre-swirl nozzle and the supply hole, numerical research and experimental verify were done to research the design problem of the receiver hole for the system. The results of numerical study show that the runway shaped receiver hole and the drilling shaped receiver hole have little difference for the system performance, and the vane shaped receiver hole has the best system performance. The increase of the length-to-diameter ratio slightly improved the system performance. Meanwhile, the circumferential angle of the receiver hole can significantly reduce the system dimensionless specific power consumption of the pre-swirl air supply system. Compared with the system using the runway shaped receiver hole, the system temperature drop efficiency of the system using the vane shaped receiver hole can increase by 14.6% under the design condition, up to 0.63. And the system dimensionless specific power consumption of it can decrease by 44.6%.
Analyze the Attentive & Bypass Bias: Mock Vignette Checks in Survey Experiments
Authors: Kane John V. , Velez Yamil R. , Barabas Jason
Published: October 2022

Respondent inattentiveness threatens to undermine causal inferences in survey-based experiments. Unfortunately, existing attention checks may induce bias while diagnosing potential problems. As an alternative, we propose “mock vignette checks” (MVCs), which are objective questions that follow short policy-related passages. Importantly, all subjects view the same vignette before the focal experiment, resulting in a common set of pre-treatment attentiveness measures. Thus, interacting MVCs with treatment indicators permits unbiased hypothesis tests despite substantial inattentiveness. In replications of several experiments with national samples, we find that MVC performance is significantly predictive of stronger treatment effects, and slightly outperforms rival measures of attentiveness, without significantly altering treatment effects. Finally, the MVCs tested here are reliable, interchangeable, and largely uncorrelated with political and socio-demographic variables.
Biosensors toward behavior detection in diagnosis of alzheimer’s disease
Authors: Sun Xiaotong , Sun Xu , Wang Qingfeng , Wang Xiang , Feng Luying , Yang Yifan , Jing Ying , Yang Canjun , Zhang Sheng
Published: October 2022

In recent years, a huge number of individuals all over the world, elderly people, in particular, have been suffering from Alzheimer’s disease (AD), which has had a significant negative impact on their quality of life. To intervene early in the progression of the disease, accurate, convenient, and low-cost detection technologies are gaining increased attention. As a result of their multiple merits in the detection and assessment of AD, biosensors are being frequently utilized in this field. Behavioral detection is a prospective way to diagnose AD at an early stage, which is a more objective and quantitative approach than conventional neuropsychological scales. Furthermore, it provides a safer and more comfortable environment than those invasive methods (such as blood and cerebrospinal fluid tests) and is more economical than neuroimaging tests. Behavior detection is gaining increasing attention in AD diagnosis. In this review, cutting-edge biosensor-based devices for AD diagnosis together with their measurement parameters and diagnostic effectiveness have been discussed in four application subtopics: body movement behavior detection, eye movement behavior detection, speech behavior detection, and multi-behavior detection. Finally, the characteristics of behavior detection sensors in various application scenarios are summarized and the prospects of their application in AD diagnostics are presented as well.
Development of 3D printable graphene oxide based bio-ink for cell support and tissue engineering
Authors: Li Jianfeng , Liu Xiao , Crook Jeremy M. , Wallace Gordon G.
Published: October 2022

Tissue engineered constructs can serve as in vitro models for research and replacement of diseased or damaged tissue. As an emerging technology, 3D bioprinting enables tissue engineering through the ability to arrange biomaterials and cells in pre-ordered structures. Hydrogels, such as alginate (Alg), can be formulated as inks for 3D bioprinting. However, Alg has limited cell affinity and lacks the functional groups needed to promote cell growth. In contrast, graphene oxide (GO) can support numerous cell types and has been purported for use in regeneration of bone, neural and cardiac tissues. Here, GO was incorporated with 2% (w/w) Alg and 3% (w/w) gelatin (Gel) to improve 3D printability for extrusion-based 3D bioprinting at room temperature (RT; 25°C) and provide a 3D cellular support platform. GO was more uniformly distributed in the ink with our developed method over a wide concentration range (0.05%–0.5%, w/w) compared to previously reported GO containing bioink. Cell support was confirmed using adipose tissue derived stem cells (ADSCs) either seeded onto 3D printed GO scaffolds or encapsulated within the GO containing ink before direct 3D printing. Added GO was shown to improve cell-affinity of bioinert biomaterials by providing more bioactive moieties on the scaffold surface. 3D cell-laden or cell-seeded constructs showed improved cell viability compared to pristine (without GO) bio-ink-based scaffolds. Our findings support the application of GO for novel bio-ink formulation, with the potential to incorporate other natural and synthetic materials such as chitosan and cellulose for advanced in situ biosensing, drug-loading and release, and with the potential for electrical stimulation of cells to further augment cell function.