Investigation of Unsteady Flow Through a Transonic Turbine Stage: Data/Prediction Comparison for Time-Averaged and Phase-Resolved Pressure Data

1992 ◽  
Vol 114 (1) ◽  
pp. 91-99 ◽  
Author(s):  
M. G. Dunn ◽  
W. A. Bennett ◽  
R. A. Delaney ◽  
K. V. Rao

This paper presents time-averaged and phase-resolved measurements of the surface pressure data for the vane and blade of a transonic single-stage research turbine. The data are compared and contrasted with predictions from an unsteady Euler/Navier–Stokes code. The data were taken in a shock-tunnel facility in which the flow was generated with a short-duration source of heated and pressurized air. Surf ace-mounted high-response pressure transducers were used to obtain the pressure measurements. The turbine was operating at the design flow function, the design stage pressure ratio, and 100 percent corrected speed. A matrix of data was obtained at two vane exit conditions and two vane/rotor axial spacings.

Author(s):  
O. Schennach ◽  
R. Pecnik ◽  
B. Paradiso ◽  
E. Go¨ttlich ◽  
A. Marn ◽  
...  

The current paper presents the results of numerical and experimental clocking investigations performed in a high-pressure transonic turbine with a downstream vane row. The objective was a detailed analysis of shock and wake interactions in such a 1.5 stage machine while clocking the vanes. Therefore a transient 3D-Navier Stokes calculation was done for two clocking positions and the three dimensional results are compared with Laser-Doppler-Velocimetry measurements at midspan. Additionally the second vane was equipped with fast response pressure transducers to record the instantaneous surface pressure for 20 different clocking positions at midspan.


2008 ◽  
Vol 130 (3) ◽  
Author(s):  
O. Schennach ◽  
R. Pecnik ◽  
B. Paradiso ◽  
E. Göttlich ◽  
A. Marn ◽  
...  

The current paper presents the results of numerical and experimental clocking investigations performed in a high-pressure transonic turbine with a downstream vane row. The objective was a detailed analysis of shock and wake interactions in such a 1.5-stage machine while clocking the vanes. Therefore, a transient 3D Navier–Stokes calculation was done for two clocking positions, and the three-dimensional results are compared with laser-Doppler-velocimetry measurements at midspan. Additionally, the second vane was equipped with fast response pressure transducers to record the instantaneous surface pressure for 20 different clocking positions at midspan.


Author(s):  
W. John Calvert ◽  
Paul R. Emmerson ◽  
Jon M. Moore

Aircraft gas turbine engines require compression systems with high performance and low weight and cost. There is therefore a continuing drive to increase compressor stage pressure ratios, particularly for military fans. To meet this need, a technology acquisition programme has been carried out by QinetiQ and Rolls-Royce. Firstly, the stage matching issues for an advanced two-stage military fan were investigated, including the effects of employing variable inlet guide vanes. From this, the requirements for the first stage together with key operating conditions for the blading were defined. The blade profiles were then designed to satisfy the range of aerodynamic conditions using a quasi-3D calculation system. A satisfactory compromise between the aerodynamic and mechanical design requirements was reached in which a blisk construction was employed for the rotor, machined from a single piece of titanium. The new stage was manufactured and tested successfully, and it achieved its target flow, pressure ratio and efficiency on the first build. Detailed measurements of the internal flows using laser anemometry and high response pressure transducers were taken. Finally, these data have been analysed and used to calibrate current 3D multi-row CFD methods.


Author(s):  
Meera Day Towler ◽  
Tim Allison ◽  
Paul Krueger ◽  
Karl Wygant

This investigation studies fast-response pressure measurements as an indicator of the onset of surge in a single-stage centrifugal compressor. The objective is to determine an online monitoring approach for surge control that does not rely on surge margin relative to maps from predictions or factory testing. Fast-response pressure transducers are installed in the suction piping, inducer, diffuser, and discharge piping. A speed line is mapped, and high-speed pressure data are collected across the compressor map. The compressor is driven into surge several times to collect pressure data between during surge and between surge events. Following testing, these data are post-processed via filtration and statistical analyses. It is determined that, when taken together, the mean and range of the standard deviation of the time signal for multiple time steps can be used to determine whether the compressor’s operating point is approaching surge for the conditions tested.


2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Yantao Yang ◽  
Hong Wu ◽  
Qiushi Li ◽  
Sheng Zhou ◽  
Jiezhi Wu

It is well recognized that vorticity and vortical structures appear inevitably in viscous compressor flows and have strong influence on the compressor performance. However, conventional analysis and design procedure cannot pinpoint the quantitative contribution of each individual vortical structure to the integrated performance of a compressor, such as the stagnation-pressure ratio and efficiency. We fill this gap by using the so-called derivative-moment transformation, which has been successfully applied to external aerodynamics. We show that the compressor performance is mainly controlled by the radial distribution of azimuthal vorticity, of which an optimization in the through-flow design stage leads to a simple Abel equation of the second kind. The satisfaction of the equation yields desired circulation distribution that optimizes the blade geometry. The advantage of this new procedure is demonstrated by numerical examples, including the posterior performance check by 3D Navier–Stokes simulation.


2009 ◽  
Vol 131 (2) ◽  
Author(s):  
James A. Tallman ◽  
Charles W. Haldeman ◽  
Michael G. Dunn ◽  
Anil K. Tolpadi ◽  
Robert F. Bergholz

This paper presents both measurements and predictions of the hot-gas-side heat transfer to a modern, 112 stage high-pressure, transonic turbine. Comparisons of the predicted and measured heat transfer are presented for each airfoil at three locations, as well as on the various endwalls and rotor tip. The measurements were performed using the Ohio State University Gas Turbine Laboratory Test Facility (TTF). The research program utilized an uncooled turbine stage at a range of operating conditions representative of the engine: in terms of corrected speed, flow function, stage pressure ratio, and gas-to-metal temperature ratio. All three airfoils were heavily instrumented for both pressure and heat transfer measurements at multiple locations. A 3D, compressible, Reynolds-averaged Navier–Stokes computational fluid dynamics (CFD) solver with k-ω turbulence modeling was used for the CFD predictions. The entire 112 stage turbine was solved using a single computation, at two different Reynolds numbers. The CFD solutions were steady, with tangentially mass-averaged inlet/exit boundary condition profiles exchanged between adjacent airfoil-rows. Overall, the CFD heat transfer predictions compared very favorably with both the global operation of the turbine and with the local measurements of heat transfer. A discussion of the features of the turbine heat transfer distributions, and their association with the corresponding flow-physics, has been included.


Author(s):  
Aws Al-Akam ◽  
Theoklis Nikolaidis ◽  
David G MacManus

At the preliminary design stage for an aero-engine, the evaluation of the nozzle performance is an important aspect as it affects the overall engine cycle behaviour. Currently, there is a lack of systematic, extensive data on the nozzle performance and its dependence on the geometric and aerodynamic aspects. This paper presents a method that can be used to build characteristic maps for a nozzle as a function of a number of geometric and aerodynamic parameters. The proposed method encompasses the design of a nozzle configuration, a parameterisation of the nozzle pressure ratio, nozzle contraction ratio, plug half-angle (β), mesh generation, and an aerodynamic assessment using the Favre-averaged Navier–Stokes method. The method has been validated against experimental performance data of a plug nozzle configuration and then used for the aerodynamic assessment. The derived nozzle maps show that the thrust coefficient ( Cfg) for this type of nozzle is significantly sensitive to the combined effect of the variation of the proposed parameters on the nozzle performance. These maps were used to build low-order models to predict Cfg, using response surface methods. The performance was assessed, and the results show that these low-order methods are capable of providing Cfg estimates with sufficient accuracy for use in preliminary design assessments.


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