Using Engine Test Data to Model Engine Performance

2012 ◽  
Author(s):  
Author(s):  
Wendy J. Matthews

HAYNES ® alloy HR-120 ® is being evaluated as a replacement for type 347 stainless steel for use in Microturbine Primary Surface Recuperators. The material has been characterized after being subjected to both steady-state and cyclic engine exposure in a Capstone C60 MicroTurbine™ operating at 100°F above the normal operating temperature. Oxide scale growth and elemental depletion has been analyzed and documented after 1,800 and 2,500 hours of exposure. A preliminary estimate of the remaining usable oxidation life has been made using a simplified parabolic model. Engine test results indicate that HR-120 has improved oxidation resistance and elemental stability.


Author(s):  
Martin Marx ◽  
Michael Kotulla ◽  
André Kando ◽  
Stephan Staudacher

To ensure the quality standards in engine testing, a growing research effort is put into the modeling of full engine test cell systems. A detailed understanding of the performance of the combined system, engine and test cell, is necessary e.g. to assess test cell modifications or to identify the influence of test cell installation effects on engine performance. This study aims to give solutions on how such a combined engine and test cell system can be effectively modeled and validated in the light of maximized test cell observability with minimum instrumentation and computational requirements. An aero-thermodynamic performance model and a CFD model are created for the Fan-Engine Pass-Off Test Facility at MTU Maintenance Berlin-Brandenburg GmbH, representing a W-shape configuration, indoor Fan-Engine test cell. Both models are adjusted and validated against each other and against test cell instrumentation. A fast-computing performance model is delivering global parameters, whereas a highly-detailed aerodynamic simulation is established for modeling component characteristics. A multi-disciplinary synthesis of both approaches can be used to optimize each of the specific models by calibration, optimized boundary conditions etc. This will result in optimized models, which, in combination, can be used to assess the respective design and operational requirements.


Author(s):  
Kuo-San Ho ◽  
Christopher Urwiller ◽  
S. Murthy Konan ◽  
Jong S. Liu ◽  
Bruno Aguilar

This paper explores the conjugate heat transfer (CHT) numerical simulation approach to calculate the metal temperature for the gas turbine cooled stator. ANSYS CFX12.1 code was selected to be the computational fluid dynamic (CFD) tool to perform the CHT simulation. The 2-equation RNG k-ε turbulence model with scalable modified wall function was employed. A full engine test with thermocouple measurement was performed and used to validate the CHT results. Metal temperatures calculated with the CHT model were compared to engine test data. The results demonstrated good agreement between test data and airfoil metal temperatures and cooling flow temperatures using the CHT model. However, the CHT calculations in the outer end wall had a discrepancy compared to the measured temperatures, which was due to the fact that the CHT model assumed an adiabatic wall as a boundary condition. This paper presents a process to calculate convection heat transfer coefficient (HTC) for cooling passages and airfoil surfaces using CHT results. This process is possible because local wall heat flux and fluid temperatures are known. This approach assists in calibrating an in-house conduction thermal model for steady state and transient thermal analyses.


Author(s):  
Sajath Kumar Manoharan ◽  
Kasram Santhosh ◽  
Mahesh P. Padwale ◽  
G. P. Ravishankar

Evaluation of engine performance during armament firing in fighter aircraft is a vital qualification aspect for airframe engine integration. Ingestion of missile’s efflux into air intake results in rapid increase of engine inlet temperatures (temperature ramps) which cause flow disturbance to the compressor. Temperature distortion caused due to armament firing and its effect on compressor stability during flight testing is evaluated. Accordingly mitigation actions are recommended for stall/surge free operations. Distortion descriptors are assessed using simulation model (engine performance program) and results compared with engine distortion limits.


Author(s):  
Balasaheb S. Dahifale ◽  
Anand S. Patil

The detailed investigation of flow behavior inside the combustion chamber and performance of engine is most challenging problem due to constraints in Experimental Data collection during testing; However, Experimental testing is essential for establishment of correlation with CFD Predictions. Hence, the baseline engine was tested at different load conditions and validated with CFD results, before it was optimized for performance improvement. The objective of the CFD Prediction was not only to optimize performance (Fuel Efficiency, Power, Torque, etc.) & Emissions Reduction, but also to assess feasibility of Performance Upgrade Potential. In the present CFD study, surface mesh and domain was prepared for the flame face, intake valve, intake valve seat, exhaust valve, exhaust valve seat and liner for closed volume cycle, between IVC and EVO using CFD code VECTIS. Finally simulations for three different load conditions were conducted using VECTIS solver. Initially, in-cylinder pressure vis a vis crank angle prediction was carried out for 100%, 75% and 50% load conditions. Then the fine tuning of (P-ϴ) diagram for different load conditions was conducted by varying different combustion parameters. Further, the engine performance validation was carried out for rated and part load conditions in terms of, IMEP, BMEP, break specific fuel consumption and power output, while NOx mass fractions were used to convert the NOx to g/kWh for comparison of emission levels with the test data. Finally optimized re-entrant combustion chamber and modified valve timing with optimum fuel injection system simulation was carried out to achieve target performance with reduced fuel consumption. A 3D CFD result showed reduction in BSFC and was in close agreement with the test data.


Author(s):  
Hans U. Burri

A brief outline is given of the method of characteristics for the analysis of one-dimensional nonsteady flow. Two typical types of experiments are discussed which indicate the degree of accuracy possible if this method is applied to machinery like the Comprex supercharger. As an example, a typical analysis is presented for one particular engine-performance point. It is possible to duplicate engine test results with acceptable accuracy.


2006 ◽  
Vol 129 (2) ◽  
pp. 312-317 ◽  
Author(s):  
Changduk Kong ◽  
Jayoung Ki

In order to estimate the gas turbine engine performance precisely, the component maps containing their own performance characteristics should be used. Because the components map is an engine manufacturer’s propriety obtained from many experimental tests with high cost, they are not provided to the customer generally. Some scaling methods for gas turbine component maps using experimental data or data partially given by engine manufacturers had been proposed in a previous study. Among them the map generation method using experimental data and genetic algorithms had showed the possibility of composing the component maps from some random test data. However not only does this method need more experimental data to obtain more realistic component maps but it also requires some more calculation time to treat the additional random test data by the component map generation program. Moreover some unnecessary test data may introduced to generate inaccuracy in component maps. The map generation method called the system identification method using partially given data from the engine manufacturer (Kong and Ki, 2003, ASME J. Eng. Gas Turbines Power, 125, 958–979) can improve the traditional scaling methods by multiplying the scaling factors at design point to off-design point data of the original performance maps, but some reference map data at off-design points should be needed. In this study a component map generation method, which may identify the component map conversely from some calculation results of a performance deck provided by the engine manufacturer using the genetic algorithms, was newly proposed to overcome the previous difficulties. As a demonstration example for this study, the PW206C turbo shaft engine for the tilt rotor type smart unmanned aerial vehicle which has been developed by Korea Aerospace Research Institute was used. In order to verify the proposed method, steady-state performance analysis results using the newly generated component maps were compared with them performed by the Estimated Engine Performance Program deck provided by the engine manufacturer. The performance results using the identified maps were also compared with them using the traditional scaling method. In this investigation, it was found that the newly proposed map generation method would be more effective than the traditional scaling method and the methods explained above.


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