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.

Laboratory Infra-Red Thermal Assessment of Laser-Sintered High-Pressure Nozzle Guide Vanes to De-Risk Engine Design Programmes

2016 ◽  
Author(s):  
Benjamin Kirollos ◽  
Thomas Povey
Keyword(s):  
Thermal Performance ◽  
Cooling System ◽  
Experimental Tests ◽  
University Of Oxford ◽  
Engine Design ◽  
Infra Red ◽  
Nozzle Guide ◽  
Processing Techniques ◽  
The University ◽  
Nozzle Guide Vanes

The continuing maturation of metal laser-sintering technology (DMLS) presents the opportunity to de-risk the engine design process by experimentally down-selecting HPNGV cooling designs using laboratory tests of laser-sintered — instead of cast — parts to assess thermal performance. Such tests could be seen as supplementary to thermal-paint-test engines, which are used during certification to validate cooling system designs. In this paper, we compare conventionally cast and laser-sintered titanium alloy parts in back-to-back experimental tests at engine-representative conditions over a range of coolant mass flow rates. Tests were performed in the University of Oxford Annular Sector Heat Transfer Facility. The thermal performance of the cast and laser-sintered parts — measured using new infra-red processing techniques — is shown to be very similar, demonstrating the utility of laser-sintered parts for preliminary engine thermal assessments. We conclude that the methods reported in this paper are sufficiently mature to make assessments which could influence engine development programmes.

Experimental Analysis of an Ultra Compact Combustor Powered Turbine Engine

2019 ◽  
Author(s):  
Brian T. Bohan ◽  
Marc D. Polanka
Keyword(s):  
Engine Performance ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Small Scale ◽  
Engine Operation ◽  
Turbine Engine ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Length Reduction ◽  
Outside Diameter

Abstract The innovative Ultra Compact Combustor (UCC) is an alternative to traditional turbine engine combustors and has been shown to reduce the combustor volume and offer potential improvements in combustion efficiency. Prior UCC configurations featured a circumferential combustion cavity positioned around the outside diameter (OD) of the engine. This configuration would be difficult to implement in a vehicle with a small, fixed diameter and had difficulty migrating the hot combustion products at the OD radially inward across an axial core flow to present a uniform temperature distribution to the first turbine stage. The present study experimentally tested a new UCC configuration that featured a circumferential cavity that exhausted axially into a dilution zone positioned just upstream of the nozzle guide vanes. The combustor was sized as a replacement burner for the JetCat P90 RXi small-scale turbine engine and fit inside the engine casing. This combustor configuration achieved a 33% length reduction compared to the stock JetCat combustor and achieved comparable engine performance across a limited operating range. Self-sustaining engine operation was achieved with a rotating compressor and turbine making this study the first to achieve operation of a UCC powered turbine engine.

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.

scholarly journals Experimental Methodology and Facility for the J69-Engine Performance and Emissions Evaluation Using Jet A1 and Biodiesel Blends

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4530 ◽  
Author(s):  
Gabriel Talero ◽  
Camilo Bayona-Roa ◽  
Giovanny Muñoz ◽  
Miguel Galindo ◽  
Vladimir Silva ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Fuel Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Experimental Tests ◽  
Experimental Methodology ◽  
Injection System ◽  
Small Scale ◽  
Gas Temperature ◽  
Maximum Increase

Aeronautic transport is a leading energy consumer that strongly contributes to greenhouse gas emissions due to a significant dependency on fossil fuels. Biodiesel, a substitution of conventional fuels, is considered as an alternative fuel for aircrafts and power generation turbine engines. Unfortunately, experimentation has been mostly limited to small scale turbines, and technical challenges remain open regarding operational safety. The current study presents the facility, the instrumentation, and the measured results of experimental tests in a 640 kW full-scale J69-T-25A turbojet engine, operating with blends of Jet A1 and oil palm biodiesel with volume contents from 0% to 10% at different load regimes. Findings are related to the fuel injection system, the engine thrust, and the emissions. The thrust force and the exhaust gas temperature do not expose a significant variation in all the operation regimes with the utilization of up to 10% volume content of biodiesel. A maximum increase of 36% in fuel consumption and 11% in injection pressure are observed at idle operation between B0 and B10. A reduction of the CO and HC emissions is also registered with a maximum variation at the cruise regime (80% Revolutions Per Minute—RPM).

A Performance Evaluation of a Three Splitter Diffuser and Vaneless Diffuser Installed on the Power Turbine Exhaust of a TF40B Gas Turbine

1998 ◽  
Author(s):  
Howard Harris ◽  
Ivan Piñeiro ◽  
Tom Norris
Keyword(s):  
Field Test ◽  
Engine Performance ◽  
Pressure Recovery ◽  
Exhaust Gas ◽  
Test Results ◽  
Gas Temperature ◽  
Vaneless Diffuser ◽  
Recovery Coefficient ◽  
Power Turbine ◽  
Exhaust Gas Temperature

A field test was conducted on a three splitter diffuser and a vaneless diffuser (no splitters) to determine, the pressure recovery coefficient, effects on engine performance, exhaust collector temperature distribution, and exhaust gas noise. This paper presents the cause of the mechanical failure of the three splitter diffuser, basic diffuser design, field test instrumentation, and the test results. The test results found the vaneless diffuser had a higher pressure recovery, created a lower back pressure, and did not raise the exhaust gas temperature (EGT) nor fuel consumption of the engine, as compared to the three splitter diffuser.

Experimental Analysis of an Ultra-Compact Combustor Powered Turbine Engine

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Brian T. Bohan ◽  
Marc D. Polanka
Keyword(s):  
Experimental Testing ◽  
Engine Performance ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Small Scale ◽  
Engine Operation ◽  
Turbine Engine ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Length Reduction

Abstract The innovative ultra-compact combustor (UCC) is an alternative to traditional turbine engine combustors and has been shown to reduce the combustor length and offer potential improvements in combustion efficiency. Prior UCC configurations featured a circumferential combustion cavity positioned around the outside diameter (OD) of the engine. This configuration would be difficult to implement in a vehicle with a small, fixed diameter and had difficulty migrating the hot combustion products at the OD radially inward across an axial core flow to present a uniform temperature distribution to the first turbine stage. This study draws from preliminary computational analysis which enabled experimental testing of a new UCC configuration that featured a smaller diameter circumferential cavity that exhausted axially into a dilution zone positioned just upstream of the nozzle guide vanes. The combustor was sized as a replacement burner for the JetCat P90 RXi small-scale turbine engine and fit inside the engine casing. This combustor configuration achieved a 33% length reduction compared to the stock JetCat combustor and achieved comparable engine performance across a limited operating range. Self-sustained engine operation was achieved with a rotating compressor and turbine making this study the first to achieve operation of a UCC-powered turbine engine.

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 Multi-Purpose Fuel: Problems That We Face

1969 ◽  
Author(s):  
John S. Siemietkowski
Keyword(s):  
Turbine Blades ◽  
Engine Performance ◽  
Problem Area ◽  
Turbine Engine ◽  
Short Period ◽  
Marine Diesel ◽  
Fuel Filter ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Cycle Endurance

A Pratt and Whitney FT4A Marine Gas Turbine Engine rated at 25,000 HP for a 100°F inlet day, was tested at the Naval Ship Engineering Center Philadelphia Division for a total of 201 hours, 15 minutes. The engine was subjected to an initial 30 hour “coking” run, conducted at 10,000 HP, 2380 rpm, to determine adverse effects on the engine under simulated destroyer type operation. Following the 30 hour coking run, the engine was subjected to a 150 hour cycle endurance operation. Salt was admitted to the inlet air. A combustion section inspection was performed at the end of the 30 hour coking run. No detrimental effects were noted at that time. An overall combustion section inspection was performed at the end of the test. A fuel manifold and nozzle spray check was performed with both acceptable for further use. First stage turbine blades showed some degree of sulfidation, while the nozzle guide vanes showed evidence of coating loss and partial penetration into the base metal (on only the uncoated vanes). The major problem area during the test was the failure of the coalescer fuel filter to function properly with Multi-Purpose fuel. Due to the higher pour point (with attendant “wax” precipitation) of the fuel in comparison with normal Marine Diesel (MIL-F-16884), plugging of the coalescer filter elements occurred in a very short period of time. Engine performance over the entire test was satisfactory approximating that of previous FT4A testing.

Assessment of the Flow Quality of a Transonic Turbine Cascade

2009 ◽  
Author(s):  
R. Woodason ◽  
A. Asghar ◽  
W. D. E. Allan
Keyword(s):  
Flow Visualization ◽  
Surface Flow ◽  
Turbine Cascade ◽  
Suction Surface ◽  
Flow Quality ◽  
Transonic Turbine ◽  
Turboshaft Engine ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Surface Flow Visualization

The assessment of flow quality through a newly constructed transonic turbine cascade is presented. Although the main objective of this research was to investigate the effect of the modification of a vane profile due to repair on pressure loss, only the results for checking the flow periodicity, two-dimensionality of the flow and transonic exit flow condition are described in this paper. The cascade blades were constructed using the profiles of nozzle guide vanes of a low pressure turbine of an in-service turboshaft engine. The assessment of the flow quality in the cascade was carried out using three methods: wall static pressure measurements at the inlet and exit of each flow passage of the cascade to check the flow periodicity, surface flow visualization using blackened paraffin oil to check the two dimensionality of the flow and thirdly, Schlieren flow visualization to verify the periodicity and transonic flow conditions at the exit of the cascade. The cascade inlet and exit wall pressure showed that the flow was nominally periodic in the cascade. The surface flow visualization of the suction surface showed that the flow was two-dimensional on approximately 70% of the central span and also indicated flow separations on the suction surface. The Schlieren flow visualization confirmed the flow periodicity and revealed the existence of shock waves on the suction surface and near the trailing edge of the blades.

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