scholarly journals The Effect of Compressor Rotor Tip Crops on Turboshaft Engine Performance

1992 ◽  
Author(s):  
Peter C. Frith
Keyword(s):  
Experimental Study ◽  
Engine Performance ◽  
Tip Clearance ◽  
Stability Margins ◽  
Compressor Rotor ◽  
Power Turbine ◽  
Normal Production ◽  
Turboshaft Engine ◽  
Engine Condition ◽  
Steady State Performance

The results from an experimental study into the effect of compressor rotor tip clearance changes on the steady-state performance and stability margins of a free-power turbine turboshaft engine are presented and discussed. This work was directed at the development of methods to diagnose engine condition from gas path measurements. It was found that the normal production suite of engine instrumentation was able to measure the deterioration in engine performance due to the implanted compressor degradation and the resultant deviations in the measured parameters from their respective nominal baselines do provide useful indicators of engine condition.

The Effect of Compressor Rotor Tip Crops on Turboshaft Engine Performance

1994 ◽  
Vol 116 (1) ◽  
pp. 184-189 ◽  
Author(s):  
P. C. Frith
Keyword(s):  
Experimental Study ◽  
Engine Performance ◽  
Tip Clearance ◽  
Stability Margins ◽  
Compressor Rotor ◽  
Power Turbine ◽  
Normal Production ◽  
Turboshaft Engine ◽  
Engine Condition ◽  
Steady State Performance

The results from an experimental study into the effect of compressor rotor tip clearance changes on the steady-state performance and stability margins of a free-power turbine turboshaft engine are presented and discussed. This work was directed at the development of methods to diagnose engine condition from gas path measurements. It was found that the normal production suite of engine instrumentation was able to measure the deterioration in engine performance due to the implanted compressor degradation and the resultant deviations in the measured parameters from their respective nominal baselines do provide useful indicators of engine condition.

Integration of 3D-CFD Component Simulation Into Overall Engine Performance Analysis for Engine Condition Monitoring Purposes

2018 ◽  
Author(s):  
C. Klein ◽  
F. Wolters ◽  
S. Reitenbach ◽  
D. Schönweitz
Keyword(s):  
Performance Analysis ◽  
Condition Monitoring ◽  
Guide Vane ◽  
Engine Performance ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Inlet Guide Vane ◽  
Cfd Model ◽  
The Impact ◽  
Engine Condition

For an efficient detection of single or multiple component damages, the knowledge of their impact on the overall engine performance is crucial. This knowledge can be either built up on measurement data, which is hardly available to non-manufacturers or –maintenance companies, or simulative approaches such as high fidelity component simulation combined with an overall cycle analysis. Due to a high degree of complexity and computational effort, overall system simulations of jet engines are typically performed as 0-dimensional thermodynamic performance analysis, based on scaled generic component maps. The approach of multi-fidelity simulation, allows the replacement of single components within the thermodynamic cycle model by higher-order simulations. Hence, the component behavior becomes directly linked to the actual hardware state of the component model. Hereby the assessment of component deteriorations in an overall system context is enabled and the resulting impact on the overall system can be quantified. The purpose of this study is to demonstrate the capabilities of multi fidelity simulation in the context of engine condition monitoring. For this purpose, a 0D-performance model of the IAE-V2527 engine is combined with a CFD model of the appropriate fan component. The CFD model comprises the rotor as well as the outlet guide vane of the bypass and the inlet guide vane of the core section. As an exemplarily component deterioration, the fan blade tip clearance is increased in multiple steps and the impact on the overall engine performance is assessed for typical engine operating conditions. The harmonization between both simulation levels is achieved by means of an improved map scaling approach using an optimization strategy leading to practicable simulation times.

The Predicted and Measured Effects of Increasing Back Pressure on the Performance of a Turboshaft Engine

2010 ◽  
Author(s):  
Marco S. Attia ◽  
Richard W. Eustace ◽  
Shane C. Favaloro
Keyword(s):  
Power Output ◽  
Engine Performance ◽  
Sensitivity Study ◽  
Test Facility ◽  
Inlet Temperature ◽  
Static Test ◽  
Tail Pipe ◽  
Fuel Flow ◽  
Power Turbine ◽  
Turboshaft Engine

This paper presents a comparison between the predicted effect of an increase in backpressure on a turboshaft helicopter engine and the actual results measured in an experimental test program. A generic engine performance program was used to perform a sensitivity study to identify the effect of increases in power turbine exit pressure (backpressure) on other engine performance parameters. The analysis showed that as the backpressure increases the engine increases fuel flow to produce a constant shaft torque (or horsepower), until the maximum power turbine entry temperature is reached. Once this occurs, fuel flow can no longer increase and thus further increases in backpressure cause a decrease in output torque. These predicted results are then compared with the actual effect as measured on a T55-GA-714A engine in a static test facility. The tests involved replacing the standard engine tail pipe with one of three shorter stub ducts which increased the backpressure by employing straight and convergent flow passages instead of the divergent passage on the standard tail pipe. The test-cell data identified that the stub ducts increase specific fuel consumption by between 0.016 and 0.039 lb/hr/hp, while the turbine inlet temperature increased by up to 108 deg F. This temperature increase means that the power output will become turbine temperature limited at a lower ambient temperature than would otherwise occur. Results showed that when temperature limiting exists the power output will be reduced by between 115 and 400 SHP depending on the choice of stub duct.

Performance of a Turboshaft Engine for Helicopter Applications Operating at Variable Shaft Speed

2012 ◽  
Author(s):  
Gianluigi Alberto Misté ◽  
Ernesto Benini
Keyword(s):  
Steady State ◽  
Engine Performance ◽  
Engine Fuel ◽  
Main Rotor ◽  
Steady State Condition ◽  
Power Turbine ◽  
Steady State Model ◽  
Optimization Routine ◽  
Turboshaft Engine ◽  
The Impact

An off-design steady state model of a generic turboshaft engine has been implemented to assess the influence of variable free power turbine (FPT) rotational speed on overall engine performance, with particular emphasis on helicopter applications. To this purpose, three off-design flight conditions were simulated and engine performance obtained with different FTP rotational speeds were compared. In this way, the impact on engine performance of a particular speed requested from the main helicopter rotor could be evaluated. Furthermore, an optimization routine was developed to find the optimal FPT speed which minimizes the engine specific fuel consumption (SFC) for each off-design steady state condition. The usual running line obtained with constant design FPT speed is compared with the optimized one. The results of the simulations are presented and discussed in detail. As a final simulation, the main rotor speed Ω required to minimize the engine fuel mass flow was estimated taking into account the different requirements of the main rotor and the turboshaft engine.

scholarly journals Steady-State and Transient Performance Simulation of a Turboshaft Engine With Free Power Turbine

1999 ◽  
Author(s):  
Changduk Kong ◽  
Jayoung Ki ◽  
Kwangwoong Koh
Keyword(s):  
Steady State ◽  
Performance Analysis ◽  
Analysis Program ◽  
Transient Performance ◽  
Gas Generator ◽  
Performance Simulation ◽  
Performance Requirements ◽  
Power Turbine ◽  
Turboshaft Engine ◽  
Steady State Performance

Steady-state and transient performance analysis programs for 200kw-class small turboshaft engine with free power turbine were developed. An existing turbojet engine was used for the gas generator of the developed turboshaft engine, and it was modified to satisfy performance requirements of this turboshaft engine. To verify the availability of steady-state performance program for this engine: the program was applied to the same type gas turbine test unit, and the analysis results were compared to experimental results. The developed transient performance analysis program using the CMF (Constant Mass flow) method was utilized to analysis in the cases of fuel step increase and the ramp increase.

scholarly journals Determination of performance and parameters for turboprop and turboshaft engine for modification through change of gas temperature before turbine

2006 ◽  
Vol 127 (4) ◽  
pp. 34-43
Author(s):  
Stanisław ANTAS
Keyword(s):  
Engine Performance ◽  
Experimental Tests ◽  
Gas Temperature ◽  
Power Turbine ◽  
Methods Of Evaluation ◽  
Modification Method ◽  
Turboshaft Engine ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes

The article presents the analysis of a commonly used performance modification method for turboprop and turboshaft engines with a free power turbine. The description of analytical and numerical methods of evaluation for a change of parameters and geometry of turbine assemblies are presented. There are also given the basic methods of changing throat area of turbine nozzle guide vanes and its influence on engine performance. The calculation methods are verified by experimental tests run by WSK “PZL-Rzeszów” S.A.

Modeling and Validation of the Thermal Effects on Gas Turbine Transients

2004 ◽  
Author(s):  
Annette E. Nielsen ◽  
Christoph W. Moll ◽  
Stephan Staudacher
Keyword(s):  
Development Program ◽  
Engine Performance ◽  
Space Structure ◽  
Tip Clearance ◽  
Model Parameters ◽  
Gas Temperature ◽  
Stability Margins ◽  
Air System ◽  
Secondary Air ◽  
Clearance Model

Secondary effects, such as heat transfer from fluid to engine structure and the resulting changes in tip and seal clearances affect component performance and stability. A tip clearance model to be used in transient synthesis codes has been developed. The tip clearance model is derived as a state space structure. The model parameters have been identified from thermo-mechanical finite element models. The model calculates symmetric rotor tip clearance changes in the turbo-machinery and symmetric seal clearance changes in the secondary air system for engine transients within the entire flight envelope. The resulting changes in efficiency, capacity and cooling air flows are fed into the performance program. Corrections for tip clearance changes on the component characteristics are derived from rig tests. The effect of seal clearance changes on the secondary air system is derived using sophisticated air system models. The clearance model is validated against FE thermo-mechanical models. The modeling method of modifying the component characteristics is verified comparing engine simulation and test data which show good agreement. Based on a representative transient maneuver typical transient overshoots in fuel flow and turbine gas temperature and changes in component stability margins can be shown. With the use of this model in the performance synthesis the transient engine performance can be predicted more accurate than currently in the engine development program.

Modeling and Validation of the Thermal Effects on Gas Turbine Transients

2005 ◽  
Vol 127 (3) ◽  
pp. 564-572 ◽  
Author(s):  
Annette E. Nielsen ◽  
Christoph W. Moll ◽  
Stephan Staudacher
Keyword(s):  
Development Program ◽  
Engine Performance ◽  
Space Structure ◽  
Tip Clearance ◽  
Model Parameters ◽  
Gas Temperature ◽  
Stability Margins ◽  
Air System ◽  
Secondary Air ◽  
Clearance Model

Secondary effects, such as heat transfer from fluid to engine structure and the resulting changes in tip and seal clearances affect component performance and stability. A tip clearance model to be used in transient synthesis codes has been developed. The tip clearance model is derived as a state space structure. The model parameters have been identified from thermomechanical finite element models. The model calculates symmetric rotor tip clearance changes in the turbomachinery and symmetric seal clearance changes in the secondary air system for engine transients within the entire flight envelope. The resulting changes in efficiency, capacity, and cooling airflows are fed into the performance program. Corrections for tip clearance changes on the component characteristics are derived from rig tests. The effect of seal clearance changes on the secondary air system is derived using sophisticated air system models. The clearance model is validated against FE thermomechanical models. The modeling method of modifying the component characteristics is verified comparing engine simulation and test data, which show good agreement. Based on a representative transient maneuver typical transient overshoots in fuel flow and turbine gas temperature and changes in component stability margins can be shown. With the use of this model in the performance synthesis the transient engine performance can be predicted more accurate than currently in the engine development program.

scholarly journals Jet A and Propane gas combustion in a turboshaft engine: performance and emissions reductions

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Ali Hasan ◽  
Oskar J. Haidn
Keyword(s):  
Combustion Process ◽  
Engine Performance ◽  
Emissions Reductions ◽  
Gas Combustion ◽  
Liquid Petroleum Gas ◽  
Performance And Emissions ◽  
Air Mixing ◽  
Turboshaft Engine ◽  
Engine Performance And Emissions ◽  
Lower Carbon

AbstractThe Paris Agreement has highlighted the need in reducing carbon emissions. Attempts in using lower carbon fuels such as Propane gas have seen limited success, mainly due to liquid petroleum gas tanks structural/size limitations. A compromised solution is presented, by combusting Jet A fuel with a small fraction of Propane gas. Propane gas with its relatively faster overall igniting time, expedites the combustion process. Computational fluid dynamics software was used to demonstrate this solution, with results validated against physical engine data. Jet A fuel was combusted with different Propane gas dosing fractions. Results demonstrated that depending on specific propane gas dosing fractions emission reductions in ppm are; NOx from 84 to 41, CO2 from less than 18,372 to less than 15,865, escaping unburned fuels dropped from 11.4 (just Jet A) to 6.26e-2 (with a 0.2 fraction of Propane gas). Soot and CO increased, this is due to current combustion chamber air mixing design.

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