scholarly journals An Air Jet Distortion Generation System

2014 ◽  
Vol 2014 ◽  
pp. 1-17
Author(s):  
M. Sivapragasam ◽  
S. Ramamurthy ◽  
M. D. Deshpande ◽  
P. White
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Total Pressure ◽  
Gas Turbine Engine ◽  
Test Facility ◽  
Generation System ◽  
Turbine Engine ◽  
Air Jet ◽  
Engine Testing ◽  
Distortion Parameters

An air jet distortion generation system is developed to simulate the distorted flow field ahead of gas turbine engines in ground test facility. The flow field of a system of four jets arranged circumferentially and issuing into a confined counterflow was studied experimentally and numerically. The total pressure distortion parameters were evaluated at the Aerodynamic Interface Plane (AIP) for several values of mass flow ratios. Since the total pressure loss distribution at theAIPis characteristically “V” shaped, the number of jets was increased to obtain total pressure distributions as required for gas turbine engine testing. With this understanding, a methodology has been developed to generate a target total pressure distortion pattern at theAIP. Turbulent flow computations are used to iteratively progress towards the target distribution. This methodology was demonstrated for a distortion flow pattern typical of use in gas turbine engine testing using twenty jets, which is a smaller number than reported in the literature. The procedure converges with a root-mean-square error of 3.836% and is able to reproduce the target pattern and other distortion parameters.

Simple Instrumentation Rake Designs for Gas Turbine Engine Testing

1996 ◽  
Author(s):  
Peter D. Smout ◽  
Steven C. Cook
Keyword(s):  
Gas Turbine ◽  
Mechanical Damage ◽  
Engine Performance ◽  
Leading Edge ◽  
Gas Turbine Engine ◽  
Calibration Data ◽  
Turbine Engine ◽  
Industry Standard ◽  
Repair Costs ◽  
Engine Testing

The determination of gas turbine engine performance relies heavily on intrusive rakes of pilot tubes and thermocouples for gas path pressure and temperature measurement. For over forty years, Kiel-shrouds mounted on the rake body leading edge have been used as the industry standard to de-sensitise the instrument to variations in flow incidence and velocity. This results in a complex rake design which is expensive to manufacture, susceptible to mechanical damage, and difficult to repair. This paper describes an exercise aimed at radically reducing rake manufacture and repair costs. A novel ’common cavity rake’ (CCR) design is presented where the pressure and/or temperature sensors are housed in a single slot let into the rake leading edge. Aerodynamic calibration data is included to show that the performance of the CCR design under uniform flow conditions and in an imposed total pressure gradient is equivalent to that of a conventional Kiel-shrouded rake.

The Effect of Heat Transfer Coefficient Increase on Tip Clearance Control in H.P. Compressors in Gas Turbine Engine

2013 ◽  
Author(s):  
Godwin Ita Ekong ◽  
Christopher A. Long ◽  
Peter R. N. Childs
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Time Constant ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Test Facility ◽  
Turbine Engine

Compressor tip clearance for a gas turbine engine application is the radial gap between the stationary compressor casing and the rotating blades. The gap varies significantly during different operating conditions of the engine due to centrifugal forces on the rotor and differential thermal expansions in the discs and casing. The tip clearance in the axial flow compressor of modern commercial civil aero-engines is of significance in terms of both mechanical integrity and performance. In general, the clearance is of critical importance to civil airline operators and their customers alike because as the clearance between the compressor blade tips and the casing increases, the aerodynamic efficiency will decrease and therefore the specific fuel consumption and operating costs will increase. This paper reports on the development of a range of concepts and their evaluation for the reduction and control of tip clearance in H.P. compressors using an enhanced heat transfer coefficient approach. This would lead to improvement in cruise tip clearances. A test facility has been developed for the study at the University of Sussex, incorporating a rotor and an inner shaft scaled down from a Rolls-Royce Trent aero-engine to a ratio of 0.7:1 with a rotational speed of up to 10000 rpm. The idle and maximum take-off conditions in the square cycle correspond to in-cavity rotational Reynolds numbers of 3.1×106 ≤ Reφ ≤ 1.0×107. The project involved modelling of the experimental facilities, to demonstrate proof of concept. The analysis shows that increasing the thermal response of the high pressure compressor (HPC) drum of a gas turbine engine assembly will reduce the drum time constant, thereby reducing the re-slam characteristics of the drum causing a reduction in the cold build clearance (CBC), and hence the reduction in cruise clearance. A further reduction can be achieved by introducing radial inflow into the drum cavity to further increase the disc heat transfer coefficient in the cavity; hence a further reduction in disc drum time constant.

Training Future Gas Turbine Performance Engineers

2007 ◽  
Author(s):  
V. Pachidis ◽  
P. Pilidis ◽  
I. Li
Keyword(s):  
Gas Turbine ◽  
Thermal Power ◽  
Engine Performance ◽  
Gas Turbine Engine ◽  
Performance Simulation ◽  
Turbine Engine ◽  
Turbine Performance ◽  
Auxiliary Power ◽  
Engine Testing ◽  
The Uk

The performance analysis of modern gas turbine engine systems has led industry to the development of sophisticated gas turbine performance simulation tools and the utilization of skilled operators who must possess the ability to balance environmental, performance and economic requirements. Academic institutions, in their training of potential gas turbine performance engineers have to be able to meet these new challenges, at least at a postgraduate level. This paper describes in detail the “Gas Turbine Performance Simulation” module of the “Thermal Power” MSc course at Cranfield University in the UK, and particularly its practical content. This covers a laboratory test of a small Auxiliary Power Unit (APU) gas turbine engine, the simulation of the ‘clean’ engine performance using a sophisticated gas turbine performance simulation tool, as well as the simulation of the degraded performance of the engine. Through this exercise students are expected to gain a basic understanding of compressor and turbine operation, gain experience in gas turbine engine testing and test data collection and assessment, develop a clear, analytical approach to gas turbine performance simulation issues, improve their technical communication skills and finally gain experience in writing a proper technical report.

Wavelet analysis of air-jet injection stall control effects in an axi-centrifugal gas turbine engine

1997 ◽  
Author(s):  
Dzu Le ◽  
Albert Owen ◽  
Donald Simon ◽  
Dzu Le ◽  
Albert Owen ◽  
...  
Keyword(s):  
Wavelet Analysis ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Jet Injection ◽  
Turbine Engine ◽  
Air Jet ◽  
Stall Control

Finite-Element Analysis of Turbulent Flow in Annular Exhaust Diffusers of Gas Turbine Engines

1991 ◽  
Vol 113 (1) ◽  
pp. 104-110 ◽  
Author(s):  
E. A. Baskharone
Keyword(s):  
Finite Element ◽  
Flow Field ◽  
Turbulent Flow ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Element Formulation ◽  
Predictive Tool ◽  
Integration Algorithm ◽  
Element Discretization ◽  
Turbine Engine

A finite-element model of the turbulent flow field in the annular exhaust diffuser of a gas turbine engine is developed. The analysis is based on a modified version of the Petrov-Galerkin weighted residual method, coupled with a highly accurate biquadratic finite element of the Lagrangian type. The elemental weight functions in the finite-element formulation are so defined to ensure upwinding of the convection terms in the flow-governing equations while reverting to the conventional Galerkin’s definition for all other terms. This approach is equivalent to altering the integration algorithm as the convection terms in the element equations are derived, with the exception that the latter technique is tailored for low-order elements of the linear and bilinear types. Numerical results of the current analysis indicate that spurious pressure modes associated with this type of inertia-dominated flow are alleviated while the false numerical diffusion in the finite-element equations is simultaneously minimized. Turbulence of the flow field is modeled using the two-layer algebraic turbulence closure of Baldwin and Lomax, and the eddy viscosity calculations are performed at variably spaced points which are different from those in the finite-element discretization model. This enhances the accuracy in computing the wall shear stress and the inner/outer layer interface location. The computational model is verified using a set of experimental data at design and off-design operation modes of the exhaust diffuser in a commercial gas turbine engine. Assessment of the results in this case is favorable and, as such, provides evidence of the model capability as an accurate predictive tool in the diffuser detailed design phase.

Optimization of Kiel geometry for better recovery factor in high temperature measurement in aero gas turbine engine

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Benny George ◽  
Nagalingam Muthuveerappan
Keyword(s):  
Temperature Measurement ◽  
Gas Turbine ◽  
Measurement Errors ◽  
Gas Turbine Engine ◽  
Critical Parameters ◽  
Turbine Engine ◽  
Design Changes ◽  
Component Efficiency ◽  
Point Pressure ◽  
Engine Testing

Abstract During gas turbine engine testing, steady-state gas-path stagnation temperatures and pressures are measured in order to calculate the adiabatic efficiencies of the major turbomachinery components. These measurements are carried out using fixed intrusive probes, which are installed at the inlet and outlet of each component. The overall uncertainty in calculated component efficiency depends on the accuracy of discrete point pressure and temperature measurement. High accuracy in measurement and prediction of measurement errors has become increasingly important if small gains in component performance needs to be achieved. The recent trend is to predict component efficiencies within ±1–2%. The present work covers different Kiel designs that have been developed in a response to this demand based on a MATLAB code and experimental evaluation. A parametric study has been carried out by varying the two most critical parameters viz. Ae/Ab ratio and L/D ratio to optimize the Kiel design. These design changes will allow measurements to be made with minimum possible errors and efficiencies to be calculated more accurately over a wider range of conditions inside a low bypass turbofan gas turbine engine.

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