bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Dynamics Characteristic of The Filling Liquid Tank
Authors: Shanglong He , Yanyang Zi , Zhenyi Chen 
Published: June 2024

Abstract
The dynamics characteristic of the rocket tank with liquid propellant in it, which takes the large part of a carrier rocket, make a great influence to the whole rocket. The tank of some model was investigated systematically by the PATRAN finite element software. Firstly, it established a finite element modal of the tank and calculated the modal frequency and shape of the empty or filling tank by the virtual fluid mass and acoustic-structure coupling analysis. Then, it contrasted the veracity and applicability of the two methods and investigated how the liquid depth and density and the middle clapboard’s thickness influenced the immanent frequency of tank. Further, the filled tank’s characteristic of response was researched by the coupled acoustic-structural analysis. Finally, it investigated how the liquid depth and density influenced the filling tank’s characteristic of response. The main conclusions are shown below:
1.The result of the filling tank’s modal is approaching to the test.
2.Augmenting the density of liquid reduces the modal frequency of tank and increases the pulsant pressure of liquid.
3.Raising the depth of liquid reduces the modal frequency of tank and increases the pulsant pressure of liquid.
The paper’s achievement and conclusion will help to avoid the coupling between the launch vehicle structure and propulsion system and improve the dynamic stability. It also can provide references for design of the new tank according to the result.
Application of On-Rotor Sensing in Planetary Gearbox Fault Diagnosis
Authors: Du Xinda , Feng Guojin , Shi Dawei , Zhen Dong , Gu Fengshou 
Published: June 2024

Abstract
Planetary gearbox is a crucial mechanical transmission component, widely used in various mechanical equipment and industrial fields. Its failure will not only cause significant economic losses, but also may bring threats to the life and health of workers. Therefore, the condition monitoring and fault diagnosis of planetary gearbox is of great significance. In this paper, a novel on-rotor sensing (ORS) technique based on a three-axis MEMS accelerometer is employed to collect vibration signals from planetary gearboxes, in which the accelerometer is mounted on the shaft near to the sun gear and rotates together with the shaft. The two orthogonal outputs of the collected vibration signals is used to construct an analytic signal and then demodulated to get the envelope spectrum, which is then used diagnose the fault in the planetary gearbox. Results show that the proposed method can effectively diagnose the sun gear crack fault, while conventional piezoelectric sensors placed on planetary gearbox casing are less capable of detecting such faults, demonstrating the superiority of ORS technology in the field of rotating machinery fault diagnosis.
Test and Analysis on High-pressure Turbine Tip Clearance Measurement of Turbofan Engine
Authors: Ren Ruidong , Tao Ye 
Published: June 2024

Abstract
The tip clearance of high-pressure turbine rotor is a key parameter for the performance and control of turbofan engine. It is of great significance to master the variation law of tip clearance for evaluating the working efficiency and performance attenuation of turbofan engine. The high-frequency dynamic analysis method based on time-frequency analysis is established. The variation law of high-pressure turbine tip clearance with engine state is obtained, and the influencing factors are analysed by simulation. The test results show that the variation law of the tip clearance of the high-pressure is consistent with the design, that is about 0∼3mm. The tip clearance of the high-pressure turbine is greatly affected by the rotor vibration. It means that we can monitor vibration of the rotor by monitoring changes in tip clearance. Real-time measurement and control adjustment should be carried out in the flight test to improve the working efficiency of the engine.
Investigation on dynamic behaviour of tin-lead welding spot of spacecraft circuit board
Authors: Zhu Jianbin , Qi Zhengpan , Yang Yanjing , Lu Dongdong , Liu Chuang , Fei Gao 
Published: June 2024

Abstract
Spacecraft shall be subjected to mechanical environments such as mechanical shocks during loading, unloading and transportation, and the shocks shall be transmitted to the circuit boards inside. There are plenty of tin-lead spots on the circuit board as there are a large number inside the spacecraft. The dynamic behaviour of tin-lead welding spot determines the anti-impact and anti-fatigue properties of the circuit board, and therefore, it is essential to investigate the dynamic behaviour of tin-lead welding spot based on sufficient experiments and accurate simulation. In this research work, the dynamic uniaxial tension at five different strain rates (0.1/s, 1/s, 10/s, 100/s and 1000/s) were performed, the morphology of the fracture surface was examined and the alloy ingredient was analyzed. Furthermore, the finite element models (FEM) of both the tensile sample and the circuit board were developed based on the modified Darveaux model and the cohesive zone method. According to the experiments and the simulation of the uniaxial tensile samples, it was the mass ratio of the tin to the lead that govern the micro mechanical properties, and the modified Darveaux model could precisely describe the stress-strain response of the welding spot. As a result, the calculated results of the impacting dynamical behaviour of the circuit board are reasonable and helpful. The modified Darveaux model and the developed simulation approach could also be applied to other welding structures experiencing impulsive loads. The investigation shall provide research support for the mechanical environment analysis of spacecraft and other mechanical impact.
Two-phase cooling system for electric vehicles’ battery
Authors: Cattani L , Malavasi M , Bozzoli F , Sciancalepore C 
Published: June 2024

Abstract
The objective of this research project is to design an innovative cooling system for effectively managing the thermal conditions of batteries in electric vehicles. Electric vehicles commonly utilize Lithium-Ion cells as their power source. Despite significant advancements in Lithium-Ion technology from an electrochemical standpoint, the thermal management of these batteries remains a formidable challenge. This is primarily due to the demanding operational conditions that Lithium-Ion cells face during battery discharge, motion, and charging. The power supply unit in electric vehicles often demands high power outputs within short durations, leading to the generation of substantial heat by the batteries. This elevated working temperature poses a risk of decreased battery performance or even malfunction. Therefore, an efficient battery thermal management system is essential to optimize the performance of the batteries. In our research project, we propose and investigate a cooling system that is directly integrated into the power supply unit. Our study introduces an innovative thermal management system that combines two-phase direct liquid cooling with pulsating heat pipes. This system provides a compelling solution by combining high thermal efficiency, passive operation, and cost-effectiveness. Within this configuration, batteries are immersed in a low-boiling dielectric fluid contained in a Plexiglas container, facilitating efficient heat exchange. Simultaneously, the pulsating heat pipe operates to manage heat spikes by promoting vapor recondensation, thereby maintaining safe operational temperatures. The proposed battery thermal management system has demonstrated remarkable efficiency, ensuring that battery temperatures remain within the recommended range even under high load conditions. A notable advantage of this cooling system is its complete passivity, eliminating the need for energy-consuming coolant circulation.
A numerical investigation on a liquid-cooled battery thermal management system: Effect of inlet temperature and flow rate
Authors: Birinci S , Albayrak M , Yazici M Y , Sarper B , Aydin O 
Published: June 2024

Abstract
Battery thermal management systems (BTMSs) and their stable operation are crucial for safety and efficiency of electrical vehicles. A BTMS utilized a cold plate is proposed in this paper for cooling of a cylindrical Li-ion Battery Pack (BP) arranged in 2×18 layout. The main focus of the study is on the effects of cooling fluid inlet temperature to cooling efficiency, and it is numerically investigated for 2C discharge rate at various flow rates from 0.1 to 1.0 l/min. The maximum temperature difference (ΔT

max
) inside the BP and the maximum cell temperature (Tmax
) are analyzed via ANSYS Fluent software. Based on the comprehensive analysis of all system evaluation criteria, it can be concluded that the optimum flow rate is 0.5 l/min, and the optimum inlet temperature is 20 °C.
Evaluation of the effects of various fan parameters on the cooking process in commercial cooking ovens
Authors: Timur R , Kahraman Z , Hacı M , Soyhan H S 
Published: June 2024

Abstract
Commercial kitchen ovens are utilized in various capacities and models within commercial enterprises, operating on either electric or gas power. Numerous parameters affect the cooking process. Particularly, for effective cooking in an oven, it’s crucial to evenly distribute airflow over the food. Correct airflow significantly impacts the cooking process. Considering the differences in processing requirements based on the characteristics and quantity of the food (such as temperature, humidity, fan speed, duration, etc.), the method of heat transfer should be primarily assessed. Non-uniform distribution of hot air during the cooking process leads to varied cooking qualities among trays within the oven. Therefore, in achieving effective cooking, factors like oven cavity, number of trays, fan geometry, fan rotation speed, direction, movement intervals, and the turbulent airflow generated by the fan in the cooking chamber need thorough examination. This study analyzed simulation data evaluating the effects of different fan geometries, fan rotation directions, and timing on heat transfer in a prototype electric commercial cooking oven using gastronomic GN-1/1 sized with 10 trays. Additionally, comparison of test and design validation data in the specially developed prototype cooking oven was conducted. Assessments were made with different fan movements (fan diameters, rotation direction, speed etc.) and a fan protection plate in front of the oven to achieve more efficient heat distribution on the food. Depending on various fan parameters, this study contributed to reducing energy consumption in the prototype commercial cooking oven.
DNS of Marangoni effects on a suspension of droplets in microgravity using the unstructured conservative level-set method
Authors: Balcázar-Arciniega N , Rigola J , Oliva A 
Published: June 2024

Abstract
The multi-marker unstructured conservative level-set (UCLS) method for two-phase flow with variable surface tension is used for the Direct Numerical Simulation of thermocapillary-driven motion of a bi-dispersed suspension of droplets in microgravity. The so-called Marangoni stresses induced by surface tension gradients on the interface lead to a coupling of the momentum transport equation and the thermal energy transport equation. The finite-volume method discretizes the transport equations on three-dimensional collocated unstructured meshes. The UCLS method performs interface capturing with mass conservation of the fluid phases, whereas the multiple marker approach circumvents the numerical coalescence of fluid particles. The fractional-step projection method solves the pressure-velocity coupling. Unstructured flux-limiters schemes discretize the convective term in transport equations. Numerical and physical findings are reported.
Review of “cold shock” cases in operation of loop heat pipes and related thermal instabilities
Authors: Ivanovskis L , Mishkinis D 
Published: June 2024

Abstract
Loop Heat Pipes (LHP) are passive two-phase heat transfer devices, driven by capillary pumps that source energy for circulation of working fluid solely from the heat source. They have a proven track record in spacecraft thermal control as well as terrestrial applications. However, LHP may experience partial or complete wick dryout and thermal instabilities at rapid power-up steps or (and) rapid condenser cooling conditions change due to a rapid inflow of subcooled liquid from the condenser into the evaporator. Such cases do not have very wide coverage in literature and are usually presented as a little nuisance in testing of a particular LHP, for which some design workaround was found. Oftentimes suggested solutions trade performance or other design merits for robustness of operation. This article aims to review such case studies where phenomena similar to the described “cold shock” affected LHP performance. The aforementioned instabilities become even more pronounced in grid-like multievaporator LHP having multiple parallel connections between capillary pumps and compensation chambers, as heat and mass transfer between those elements becomes less definite and can eventually increase the heat leak into compensation chambers. Vulnerability of LHP with distributed network of evaporators to seemingly “safe” transient regimes fosters deeper analysis of the “cold shock” phenomenon. With comprehensive definition to the problem and a list of research questions, technical measures for getting rid of it in perspective LHP designs can be foreseen.
Simplified computational model of the primary and secondary freeze-drying process of agriculture and marine foods
Authors: Piechnik E , Stebel M , Palacz M , Haida M , Bodys J , Melka B , Ciesielska A , Smolka J , Nowak A J 
Published: June 2024

Abstract
The food freeze-drying is a low-pressure and low-temperature dehydration process during which the following basic steps can be distinguished: (1) freezing of the food product in the chamber, (2) vacuuming of the freezing chamber, (3) ice sublimation from a frozen food product (primary drying), (4) removing the water bound in the food product (secondary drying). This paper discusses a simplified 1-D in-house computational model of the primary and secondary freeze-drying processes, i.e. stages 3 and 4. In particular, it allows for times prognosis of both, primary and secondary freeze-dryings separately. Finally, that analysis provided the basis for the proper selection of the thermal parameters in the process. Complex analysis of the drying process can also result in the reduction of energy consumption. In this project the experimental campaign together with computer simulations has been performed for various food products including meat, fruit and vegetables.
Numerical analysis of transport phenomena in a steam reforming reactor with optimal multi-segments catalyst distribution
Authors: Pajak M , Brus G , Kimijima S , Szmyd J S 
Published: June 2024

Abstract
The contemporary industrial trends pursue alternative energy sources, to substitute fossil fuels. The current direction is induced by concerns regarding exhausting natural resources and the environmental impact of the technologies rising globally. Conventional technologies have a dominant share of the current energy market. The most crucial issue with current technology is the emission of greenhouse gases and their negative impact on climate. One of the possible approaches to limit the issue of emissions is the steam reforming of natural gas, leading to the production of hydrogen. Fuel cells are a robust technology, able to conduct a catalytic conversion of hydrogen and oxygen, for the direct production of electrical energy. Fuel cells are one of the most environment-friendly technologies to this day, as their exhaust gases mostly consist of steam. Currently, almost 50% of the hydrogen produced is acquired via hydrocarbons reforming. The process described in the presented analysis occurs between methane and steam. The presented numerical analysis regards small-scale reactors, which are more suitable when it comes to the processing of distributed or stranded resources for hydrogen production To optimize the small-scale unit’s performance, the macro-patterning strategy is introduced. Steam reforming has a strong endothermic character and tends to produce unfavorable thermal conditions. The process enhancement is acquired by introducing non-catalytic regions to the catalytic insert geometry. The non-catalytic segments are introduced to suppress the reaction locally, decreasing the magnitude of temperature gradients. Unification of the temperature distribution is proven to increase the reforming’s effectiveness. The presented analysis introduces a new approach to the catalytic insert division, to investigate if a complete temperature field unification is possible. The catalytic insert is simultaneously divided along the reactor’s radius and length, resulting in a set of concentric rings, placed along the reactor’s axis. The calculations are conducted using in-house numerical procedure, coupled with a genetic algorithm. The algorithm optimizes the process effectiveness by modification of the segment’s alignment and porosity.
Simple model of liquid piston compressor
Authors: Cerkovnik N , Čurović L , Prezelj J 
Published: June 2024

Abstract
The study proposes a new 0D thermodynamic model for the fast and simple evaluation of Liquid Piston compressors whose geometry and operation are determined by large number of parameters. With the proposed model, the evaluation of the parameters becomes easier, more dependencies are found and the understanding of the influences of parameter changes is deepened. Therefore, optimal designs for the mentioned machines can be created and tested experimentally. During the study, the model was validated with experimental and CFD data, and the results showed good agreement. It was found that evaluation criteria need to be defined for each set of geometric and operational parameters in order to compare the designs.
CFD design and optimization of a multi-probe device for temperature measurements in Waste-to-Energy plants
Authors: Grossi G , Arpino F , Canale C , Cortellessa G , Ficco G , Lombardi T 
Published: June 2024

Abstract
The temperature of exhaust gases is an essential parameter to monitor in Waste-to-Energy (WtE) plants, since it significantly affects energy efficiency, pollutant emissions and materials’ integrity. Current methods for monitoring gas temperature in such plants (i.e., thermocouples, infrared pyrometers, and aspirated thermocouples) exhibit shortcomings in both accuracy and reliability when used in environments where radiative heat exchange plays an important role. In previous research, by means of Computational Fluid Dynamics (CFD) simulations, the authors designed a new multi-probe device, with the aim of mitigating the issues associated with these commonly adopted techniques. The newly designed measuring device is herein further characterized by means of multi-region CFD simulations, to investigate any local thermal-fluid dynamics effects which may impair the measurement, due to the mutual influence of the ducts where the sensors are located. Results have shown that the mutual influence is not significant, confirming the validity of the designed shape.
Impact of variation of the cooling system operating strategy on energy efficiency and waste heat quality: a preliminary investigation on a hybrid-cooled data centre
Authors: Testa L , Stuart P , O’Donnell C , Persoons T 
Published: June 2024

Abstract
The growing demand for digital services is leading to a rapid increase of the number of data centres worldwide. Because of the large amount of energy required to power these facilities and the consequent challenges for the energy system and the environment, efforts are made to discover new solutions that allow a more prudent use of energy without compromising the quality of the service provided. One of these potentially viable solutions is a less conservative configuration of the operating strategy of the cooling system, which can request up to 30% of the total power absorbed by a data centre. This paper is a first estimation of the benefits in terms of power savings and waste heat quality that would follow the implementation of this solution on the Green DC, a data centre based in Dublin, Ireland. The Green DC is installed within a university and provides a variety of services, like HPC and online lecture streaming.
Experimental analysis of an innovative geo-exchange system installed on the island of Ischia, in southern Italy
Authors: Guida V , Massarotti N , Mauro A 
Published: June 2024

Abstract
The need to use efficient and eco-friendly air conditioning systems is a fundamental requirement for today’s society. In this context, low and medium enthalpy geothermal energy plays a crucial role. The research and development activities carried out in the present work have made it possible to successfully design and analyze an innovative technology capable of supplying thermal energy to environments without pumping fluid from the subsoil. The proposed system is based on the use of a downhole heat exchanger (DHE). The authors have developed an innovative system for the sustainable use of low and medium enthalpy geothermal energy, installed on the island of Ischia, near Napoli, in southern Italy. The proposed system is based on the use of an ad hoc designed DHE, capable of optimizing the heat transfer with the subsoil, without the need to withdraw fluid from the aquifer. A numerical finite element model was developed to study the interaction between the DHE, the well and the surrounding aquifer. The experimental set-up consists of the heat exchanger and an above ground system, necessary to test the efficiency of the exchanger. The DHE is inserted inside a geothermal well made with a steel casing, equipped with a filtering section in correspondence of the DHE, in order to increase the heat transfer performance due to increased convection with the surrounding aquifer. The experimental data show that the DHE allows to exchange more than 40 kW with the ground, obtaining overall heat transfer coefficient values larger than 450 W/m2 K.
Simulation of non-Newtonian gas-focused micro-jets in chocked gas flow regime
Authors: Zahoor R , Bajt S , Šarler B 
Published: June 2024

Abstract
Stable liquid jets are crucial for successful serial crystallography experiments. They are produced from gas dynamic virtual nozzles (GDVNs), where the liquid from an inner capillary is focused by a co-flowing gas from an outer converging capillary. Our previously investigated non-Newtonian jets with incompressible and compressible focusing gas under atmospheric conditions were extended towards compressible chocked gas under vacuum conditions. An axisymmetric GDVN was considered with a fixed gas flow rate of 15 mg/min and liquid flow rate of 40 µl/min. A mixture formulation of the laminar compressible multiphase problem was solved within finite volume method and volume of fluid framework. The jet lengths, diameters, velocities, and temperatures were analysed as a function of the power-law non-Newtonian modification of reference water. It is observed that the jets under vacuum conditions are thinner for Newtonian and shear-thickening fluids than those in the atmosphere. The jet length increases from shear-thinning to shear-thickening rheology but is not affected by the pressure. The shear produced at the nozzle outlet is similar for both pressure conditions but increases in downstream directions for vacuum conditions. Gas expanding into vacuum cools by ~100-150 K while the temperature of the liquid jet drops only by a few K.