bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atmospheric Tests of a Full Scale Gas Turbine Burner Fed With Blast Furnace Gas and Coke Oven Gas
Authors: Bertolotto Edoardo , Amato Alberto , Guoqiang Li 
Published: November 2019

Abstract
The present paper describes atmospheric experimental tests of a new Ansaldo Energia full scale burner which was designed to burn fuels byproduct of steel making processes (mixtures of Blast-Furnace Gas (BFG) and Coke-Oven Gas (COG)), characterized by very low heating values (LHV∼2–3.5 MJ/kg) and very low stoichiometric air/fuel ratios (∼0.5–1 kg/kg). In particular, flame stability and blow-out margins were assessed for different burner variants and fuel compositions such as pure BFG, blends of BFG with increasing content of COG, and also a synthetic mixture of natural gas, hydrogen and nitrogen (NG/H2/N2). Except for pressure, all burner inlet conditions were simulated as in the actual gas turbine engine. The best performing burner among those tested demonstrated an excellent burning stability behavior over a wide operating range and stably burned pure BFG without any supplementary fuel. Furthermore, considering that in most operating concepts gas turbine engines for Ultra-Low BTU applications require a back-up fuel (such as oil, propane or natural gas) to ignite and ramp up or to perform load-rejections, the present atmospheric tests also assessed maneuvers to switch from natural gas operation to syngas operation. Also in this type of dual-fuel operation the burner demonstrated a wide flame stability range.
Theoretical and Experimental Investigation of a Small-Scale, High-Speed, and Oil-Free Radial Anode Off-Gas Recirculation Fan for Solid Oxide Fuel Cell Systems
Authors: Wagner Patrick H. , Van herle Jan , Schiffmann Jürg 
Published: November 2019

Abstract
The Laboratory for Applied Mechanical Design (LAMD) designed, manufactured, and experimentally tested a novel recirculation fan for a 10 kWe solid oxide fuel cell (SOFC). The fan uses oil-free bearings, more specifically herringbone-grooved journal and spiral-grooved thrust gas bearings. The radial inducer-less fan with a tip diameter of 19.2 mm features backward-curved prismatic blades with constant height. Prior to coupling the recirculation fan with the SOFC, the fan was experimentally characterized with air at 200 °C. At the nominal point of 168 krpm, the measured inlet mass flow rate is 4.9 kgh−1, the total-to-total pressure rise 55 mbar, the isentropic total-to-total efficiency 55 %, and the power 18.3 W. This paper compares the experimental data towards a computational fluid dynamic simulation of the full fan impeller and volute suggesting an excellent correlation at the nominal point what validates the numerical approach. However, the heat flows crossing the fan fluid domain, have an increased effect at off-design conditions, thus the experimental results need careful consideration. The fan backface leakage has negligible impact on the measurements.
Validation of a Turbine Blade Component Test With Frictional Contacts by Phase-Locked-Loop and Force-Controlled Measurements
Authors: Schwarz Stefan , Kohlmann Lukas , Hartung Andreas , Gross Johann , Scheel Maren , Krack Malte 
Published: November 2019

Abstract
In this paper, a validation approach for a turbine blade component test with frictional contacts is presented. The investigated system is derived from a high cycle fatigue test setup, where a turbine blade is base-excited in the clamped blade foot. The setup has been extended by laser scanning vibrometry, a force measurement platform and feedback-controllers for both force level and phase. At first, a conventional validation of a linearized model of the system is performed at low amplitudes to ensure the correct modal basis for model reduction. After that, the nonlinear behavior around the fundamental mode is analyzed in detail. Frequency responses for different excitation levels and backbone curves are measured and assessed regarding repeatability and robustness of the measurement chain. Among other effects, overhanging branches of the frequency response were encountered. Nonlinear, amplitude-dependent modal frequencies and damping ratios are identified from the backbone curves. This data forms the validation basis for a reduced-order model of the system considering nonlinear friction in the blade foot. The correlation of measurement and simulation is investigated and advantages and shortcomings of the different validation metrics are discussed.
Large-Eddy Simulations of Heat Transfer Within a Multi-Perforation Synthetic Jets Configuration
Authors: Esnault Soizic , Duchaine Florent , Gicquel Laurent 
Published: November 2019

Abstract
Synthetic jets are produced by devices that enable a suction phase followed by an ejection phase. The resulting mean mass budget is hence null and no addition of mass in the system is required. These particular jets have especially been considered for some years for flow control applications. They also display features that can become of interest to enhance heat exchanges, for example for wall cooling issues. Synthetic jets can be generated through different mechanisms, such as acoustics by making use of a Helmholtz resonator or through the motion of a piston as in an experience mounted at Institut Pprime in France. The objective of this specific experiment is to understand how synthetic jets can enhance heat transfer in a multi-perforated configuration. As a complement to this experimental set up, Large-Eddy Simulations are produced and analysed in the present document to investigate the flow behavior as well as the impact of the synthetic jets on wall heat transfer.
The experimental system considered here consists in a perforated heated plate, each perforation being above a cavity where a piston is used to control the synthetic jets. Placed in a wind tunnel test section, the device can be studied with a grazing flow and multiple operating points are available. The one considered here implies a grazing flow velocity of 12.8 m.s−1, corresponding to a Mach number around 0.04, and a piston displacement of 22 mm peak-to-peak at a frequency of 12.8 Hz. These two latter parameters lead to a jet Reynolds number of about 830.
A good agreement is found between numerical results and experimental data. The simulations are then used to provide a detailed understanding of the flow. Two main behaviours are found, depending on the considered mid-period. During the ejection phase, the flow transitions to turbulence and the formation of characteristic structures is observed; the plate is efficiently cooled. During the suction phase the main flow is stabilised; the heat enhancement is particularly efficient in the hole wakes but not between them, leading to a heterogeneous temperature field.
New Methods for Secondary Flow Phenomena Visualization and Analysis
Authors: Straccia Mattia , Hofmann Rodolfo , Gümmer Volker 
Published: November 2019

Abstract
This work focuses on presenting new techniques for the visualization of Secondary Flow Phenomena (SFP) in transonic turbomachinery. Here, Rotor 37 has been used to develop and apply these techniques in order to study vortices, shocks and secondary flows. They are also used to provide a comparison between turbulence models in Ansys CFX environment, here the Spalart-Allmaras (SA) and Shear Stress Tensor (SST) turbulence models. The scope of this paper is to give an improved understanding of SFP and how their onset and evolution are influenced from the turbulence model.
The analysis is based on results of three-dimensional steady-state RANS simulations, for operating points between design point and near-stall condition, achieved by varying the outlet static pressure radial equilibrium distribution at the rotor exit. The new visualization techniques highlight important flow field features less investigated in previous research works, in particular secondary weak strength vortices. They will give a better visualization of and insight to the interaction of the passage shock and the tip leakage vortex, the interaction between vortices and boundary layers and the interaction of the shock wave and endwall boundary layers.
Humidified Micro Gas Turbine for Range Extended Electric Vehicles: Thermodynamic Performance Assessment
Authors: De Paepe Ward , Montero Carrero Marina , Pappa Alessio , Bricteux Laurent , Contino Francesco 
Published: November 2019

Abstract
To reduce the emission of greenhouse gases, there is nowadays a strong focus on the electrification of transportation, especially personal vehicles. One of the main limitations of this trend is the limited range of Electrical Vehicles (EVs) due to the rather low energy density of batteries compared to liquid fossil fuels. Adding a range extender allows for a significant increase of the vehicle driving range. Typical range extenders are Internal Combustion Engine (ICE) based. Although micro Gas Turbines (mGTs) are not adequate for continuous change of load, as would be the case when used as direct power source, operating them as range extender offers large potential, especially given their higher power-to-weight ratio than ICEs, but also due to their lower emissions, vibration levels and maintenance requirements. The main drawback of the mGT compared to the ICE is its lower electrical efficiency. Humidification of the mGT cycle allows boosting its performance and by doing so making it more compatible.
In this paper, we investigate the feasibility of applying a (humidified) mGT as a range extender in EVs. In this investigation, we considered a small vehicle for use in urban area. The option of using an mGT as range extender (standard and humidified) is compared to the standard ICE based range extender. Aspen plus is used to assess the engines performance, showing that the humidified mGT has the highest potential in terms of fuel consumption reduction and range extension. Moreover, the humidified mGT presents similar performance compared to an ICE, leading to the same specific energy consumption. In addition, different pathways to compensate for the water consumption (exhaust gas condensation) are studied and discussed, revealing that the vehicle does not need external input of water.
Surrogate-Assisted Modeling and Robust Optimization of a Micro Gas Turbine Plant With Carbon Capture
Authors: Giorgetti Simone , Coppitters Diederik , Contino Francesco , De Paepe Ward , Bricteux Laurent , Aversano Gianmarco , Parente Alessandro 
Published: November 2019

Abstract
The growing share of wind and solar power in the total energy mix has caused severe problems in balancing the electrical power production. Consequently, in the future, all fossil fuel-based electricity generation will need to be run on a completely flexible basis. Micro Gas Turbines (mGTs) constitutes a mature technology which can offer such flexibility. Even though their greenhouse gas emissions are already very low, stringent carbon reduction targets will require them to be completely carbon neutral: this constraint implies the adoption of post-combustion Carbon Capture (CC) on these energy systems. To reduce the CC energy penalty, Exhaust Gas Recirculation (EGR) can be applied to the mGTs increasing the CO2 content in the exhaust gas and reducing the mass flow rate of flue gas to be treated. As a result, a lower investment and operational cost of the CC unit can be achieved. In spite of this attractive solution, an in-depth study along with a robust optimization of this system has not yet been carried out. Hence, in this paper, a typical mGT with EGR has been coupled with an amine-based CC plant and simulated using the software Aspen Plus®. A rigorous rate-based simulation of the CO2 absorption and desorption in the CC unit offers an accurate prediction; however, its time complexity and convergence difficulty are severe limitations for a stochastic optimization. Therefore, a surrogate-based optimization approach has been used, which makes use of a Gaussian Process Regression (GPR) model, trained using the Aspen Plus® data, to quickly find operating points of the plant at a very low computational cost. Using the validated surrogate model, a robust optimization using a Non-dominated Sorting Genetic Algorithm II (NSGA II) has been carried out, assessing the influence of each input uncertainty and varying several design variables. As a general result, the analysed power plant proves to be intrinsically very robust, even when the input variables are affected by strong uncertainties.
Gas Turbine Co-Firing of Steelworks Ammonia With Coke Oven Gas or Methane: A Fundamental and Cycle Analysis
Authors: Hewlett S. G. , Valera-Medina A. , Pugh D. G. , Bowen P. J. 
Published: November 2019

Abstract
Following on from successful experimental trials employing ammonia/hydrogen blends in a model gas turbine combustor, with favorable NOx and unburned fuel emissions, a detailed numerical study has been undertaken to assess the viability of using steelworks by-product ammonia in gas turbines. Every metric ton (tonne) of steel manufactured using a blast furnace results in approximately 1.5 kg of by-product ammonia, usually present in a vapor form, from the cleansing of coke oven gas (COG). This study numerically investigates the potential to utilize this by-product for power generation. Ammonia combustion presents some major challenges, including poor reactivity and a propensity for excessive NOx emissions. Ammonia combustion has been shown to be greatly enhanced through the addition of support fuels, hydrogen and methane (both major components of COG). CHEMKIN-PRO is employed to demonstrate the optimal ratio of ammonia vapor, and alternatively anhydrous ammonia recovered from the vapor, to COG or methane at equivalence ratios between 1.0 and 1.4 under an elevated inlet temperature of 550K. Aspen Plus was used to design a Brayton-Rankine cycle with integrated recuperation, and overall cycle efficiencies were calculated for a range of favorable equivalence ratios, identified from the combustion models. The results have been used to specify a series of emissions experiments in a model gas turbine combustor.
A Novel Solid-State Additive Manufacturing Technology in Support of Turbomachinery Sustainment
Authors: Cox Chase D. , Hardwick Nanci 
Published: November 2019

Abstract
Maintenance, repair, and overhaul activities are necessary and critical, often repeated, operations which occur during the lifecycle of turbomachinery components and assemblies. The ability to extend the life and performance of parts via sustainment type activities currently in service offers a significant and beneficial financial impact for both the manufacturers of these components as well as their end-users. Additive manufacturing not only enables manufacturers the ability to “print” complex geometries in a wide array of materials including metals but, in some instances, also offers a novel opportunity for the repair and overhaul of existing components. The MELD process is quickly becoming an established AM technology which has repeated demonstrated success in additive manufacturing, repair, coating, and joining operations. The MELD process creates fully-dense products with near wrought properties, and reduced distortion, at very high deposition rates. MELD is a solid-state process, which yields parts with superior mechanical properties as compared to those produced by liquid-state metal deposition or spray forming processes. It is an open atmosphere process, allowing for extreme scalability. By the nature of the process all depositions, repairs, and coatings are fully dense and do not require any additional processing for densification such as sintering or HIP. Potential disadvantages include the inability to construct complex, finely featured products. The MELD process is well suited for the fabrication, repair, and overhauling of large-scale components as it is not restricted to space restrictive powder beds or vacuum chambers. In addition, the MELD process carries a lower operating cost (comparable to a CNC mill) and requires less infrastructure than traditional melt-based AM technologies. In this presentation, the MELD process will be explored as a viable method for additive manufacturing, coating, repair, and joining operations. Unique attributes will be considered along with resulting advantages and disadvantages. Specific high-level real-world examples presented will include MELD applications which highlight the repair of a cast non-fusion weldable Mg helicopter gearbox housing, the joining and repair operations of simulated damage (holes and cracks) using 2XXX and 7XXX series aluminum alloys, the application of nickel-based super-alloy coatings on high-strength low alloy steels, and the additive manufacture and repair of titanium alloys.
Methodology to Optimize and Predict the Measurement Point Distribution for Compressor Mapping on the Hot-Gas Test Bench
Authors: Mai Holger , Kaufmann André , Vogt Mathias 
Published: November 2019

Abstract
Current and future legal requirements for internal combustion engines (ICE) are increasing the complexity of modern charging systems. Test system manufacturers are facing high demands in terms of hardware specifications and methods for turbocharger testing on a hot-gas test bench. Innovative test systems and methodologies help to improve the quality of the turbocharger and engine matching process and significantly optimize the operating strategy in engine process simulation, especially in the early development and design phase.
The compressor and turbine characteristic maps are the most important sources of information in order to quantify the performance of the turbocharger. This is achieved in practice by thermodynamically evaluating turbochargers on the hot-gas test bench under test conditions that are as close as possible to real engine operation conditions. Turbocharger compressor mapping relies on the measurement of pressure and temperature upstream and downstream of the compressor at designated operating points. For use in the turbocharger matching process, mostly equidistant points on the operation line between surge and choke are required. Comparison to Computational Fluid Dynamics (CFD) requires a higher density of measurement points, especially in the vicinity of maximum compressor efficiency to analyze different geometries. The requirement to measure different point distributions at fixed rotational speed is the logical consequence.
The primary objective of this paper is to develop and evaluate a methodology that allows different operating point distributions of compressor speed lines for the compressor mapping on the hot-gas test bench. The secondary objective deals with the prediction of the measurement points with respect to pressure ratio and volume flow rate at a fixed rotational speed. This facilitates the pre-selection of settings on the hot-gas test bench.
An Experimental Study of Impingement Cooling on Latticework in a Wide Channel
Authors: Xu Jin , Lu Ruishan , Zhang Ke , Lei Jiang , Wu Junmei 
Published: November 2019

Abstract
Previous researches on latticework were focused on the convective heat transfer performance on pressure and suction sides of a blade model. Besides, it has an effect on leading edge by impingement. Thus, the present study provides heat transfer enhancement and pressure loss of jet impingement of a latticework on side wall in a wide channel (AR = 4). Two latticework configurations with impingement effects are employed in this study. Three kinds of sub-channel models are used in this experiment, which is according to different cooling designs. The angle of the rib is 45° and the numbers of subchannel are 4, 6 and 8, respectively. Reynolds number range is from 10000 to 30000 with an increment of 10000. The wall temperature is obtained by using wide band liquid crystal technique, and then the heat transfer coefficients on the target surface of the channel are achieved. Pressure drop of the latticework channel is also measured by pressure taps. The result shows that these two latticework models have different flow and heat transfer characteristics. The Nusselt number distribution is not similar to that of traditional jet array impingement. The range of Nusselt number enhancement is 2.3 to 6.4 compared to that of a smooth convective channel (the Nusselt number is based on the channel hydraulic diameter). The jet-to-target distance could reduce the overall averaged heat transfer on side wall. But it could also lead to a high Nu region. To the normal lattice model, more sub-channels there are, more pressure loss it has. To the novel lattice model, sub-channel number cannot affect the pressure loss, but the jet-to-target distance could affect the friction factor obviously.
Vibration Characteristics of Rotor System Considering Gear Meshing
Authors: Hong Jie , Xu XiRu , Jiang LiMing , Ma YanHong 
Published: November 2019

Abstract
Spiral bevel gears are essential units in the accessories system of the aero-engine. The rotor transmits torque to the accessories system through the spiral bevel gears, which also change the direction of rotation. With the wide application of elastic support and the reduction in the number of bearing frames, the fulcrum stiffness and the rotor shaft stiffness is on the same order of magnitude of the gear meshing stiffness. For these multi-axis gear transmission systems, the effects of time-varying relative displacement between the gear meshing points and its additional constraint on the dynamic characteristics of the rotor ought be considered. In this paper, a coupled mechanical model of the bevel gear-coupled two-shaft rotor system is established. Besides, the coupled vibration mode of the gear-rotor system is studied. Finally, the influence of nonlinearity relative displacement and its additional constraint on the vibration characteristics of the rotor system are analyzed. The results show that the driven gear will produce elastic additional constraint on the rotor under the specific vibration mode. When the gear meshing stiffness is on the same magnitude as the support stiffness of the rotor, and the relative vibration displacement between the driving and driven gears is large enough, it is necessary to consider the influence of additional constraints on the rotor dynamics. The analysis in this paper provide a reference for dynamic optimization designs, fault monitoring and diagnosis of gear-rotor systems.
Using Optimization in Industrial Multi-Point Radial Compressor Design: Map Correction
Authors: Childs Edward P. , Deserranno Dimitri , Bagi Akshay 
Published: November 2019

Abstract
The application of Surrogate-Based Optimization (SBO) to the industrial design process for a radial compressor with two operating points is described. The design specification includes two operating points at mass flow rates differing by a factor of three, and efficiency and pressure ratio targets for each point. The base case, while roughly sized from 1D analysis, fails to achieve the pressure ratio targets. In this paper, the optimization focusses on correcting the two speed-line map of total to static pressure ratio vs. mass flow rate. “Smart parameterization”, combining independent and dependent geometric parameters, and yielding reasonable geometries for most input combinations, coupled with efficient SBO, with separate models for response surface modeling and failure prediction, yields a design achieving the targets in just 57 CFD runs. FINE/Turbo [1] is used as the CFD analysis code and FINE/Design3D [2] and MINAMO [3] as the multi-objective optimizer.