A Simple Procedure to Compute Losses in Transonic Turbines Cascades

1985 ◽  
Author(s):  
Francesco Martelli ◽  
Alberto Boretti
Keyword(s):  
Transonic Flow ◽  
Simple Procedure ◽  
Turbine Blades ◽  
Wave Interaction ◽  
Integral Boundary ◽  
Shock Wave Interaction ◽  
Time Requirements ◽  
Time Marching ◽  
Shock System ◽  
Marching Method

The prediction of losses in transonic flow in turbines is an important step in the design of turbine stages, but at the same time requirements of simplicity and speed are needed to allow the work of designers. The paper presents a procedure developed to match this goal. It uses classical codes, experimental correlations and simple geometrical models of the shock system. The result of a time marching method with standard mesh is used to run an Integral Boundary layer calculation in which shock wave interaction effects have been included. The shock system is made up of this information plus empirical correlation and a suitable procedure. A mixing calculation is then performed to get the downstream total pressure. The method has been tested with various kinds of turbine blades of which losses and data for calculations have been published. The results are quite good and the procedure appears simple and fast.

The Aerodynamics of Trailing-Edge-Cooled Transonic Turbine Blades: Part 2 — Theoretical and Computational Approach

1997 ◽  
Author(s):  
Mathias Deckers ◽  
John D. Denton
Keyword(s):  
Transonic Flow ◽  
Theoretical Study ◽  
Computational Study ◽  
Control Volume ◽  
Turbine Blades ◽  
Computational Approach ◽  
Trailing Edge ◽  
Time Marching ◽  
Transonic Turbine ◽  
Volume Method

A theoretical and computational study into the aerodynamics of trailing-edge-cooled transonic turbine blades is described in this part of the paper. The theoretical study shows that, for unstaggered blades with coolant ejection, the base pressure and overall loss can be determined exactly by a simple control volume analysis. This theory suggests that a thick, cooled trailing edge with a wide slot can be more efficient than a thin, solid trailing edge. An existing time-marching finite volume method is adapted to calculate the transonic flow with trailing edge coolant ejection on a structured, quasi-orthogonal mesh. Good overall agreement between the present method, inviscid and viscous, and experimental evidence is obtained.

The Effect of Sweep on Conditions at Separation in Turbulent Boundary-Layer/Shock-Wave Interaction

1977 ◽  
Vol 28 (2) ◽  
pp. 111-122 ◽  
Author(s):  
D F Myring
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Turbulent Boundary Layer ◽  
Pressure Rise ◽  
Prediction Method ◽  
Wave Interaction ◽  
Reynolds Numbers ◽  
Approximate Analysis ◽  
Integral Boundary ◽  
Shock Wave Interaction

SummaryAn approximate analysis of conditions at separation produced by turbulent boundary-layer/shock-wave interaction is presented for swept, cylindrically symmetric flows. An integral boundary-layer prediction method is used, incorporating Johnston crossflow profiles. The results indicate a marked reduction in pressure rise required to produce separation as sweep is increased. At low Reynolds numbers the skin friction at separation is inferred to be small, whereas at higher Reynolds numbers the presence of a vigorous streamwise flow may be detected. In the limiting case of zero sweep, or two-dimensional flow, predictions using the approximate analysis are shown to compare well with experimental results of pressure rise to separation.

Nonstationary phenomena in the region of shock-wave interaction with a boundary layer at transonic flow velocities

2017 ◽  
Vol 43 (6) ◽  
pp. 570-573 ◽  
Author(s):  
A. A. Sidorenko ◽  
A. D. Budovskii ◽  
P. A. Polivanov ◽  
O. I. Vishnyakov
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Transonic Flow ◽  
Wave Interaction ◽  
Shock Wave Interaction ◽  
Flow Velocities

Investigations of Transonic Turbine Cascade With High Stagger and Low Solidity

1979 ◽  
Author(s):  
M. Inoue ◽  
S. Yamaguchi ◽  
M. Kuroumaru
Keyword(s):  
Transonic Flow ◽  
Laval Nozzle ◽  
Experimental Studies ◽  
Flow Characteristics ◽  
Chord Length ◽  
Turbine Cascade ◽  
Trailing Edge ◽  
Time Marching ◽  
Shock System ◽  
Transonic Turbine

In order to clarify the transonic flow characteristics of a turbine cascade with high stagger, low solidity and small deflections, experimental studies were carried out by shortening the chord length of a “Laval-nozzle shaped” blade with thick trailing edge. The behavior of the shock system depends on the amount of overlap between the blades. The relations between the behavior and the performances were discussed in detail. The results may be applied to more standard sections. Lastly, validity of an appropriate time marching analysis for the highly staggered cascade was investigated by comparing with the experiment.

Numerical Prediction of Turbine Profile Loss

1990 ◽  
Author(s):  
L. Xu ◽  
J. D. Denton
Keyword(s):  
Turbine Blades ◽  
Surface Friction ◽  
Trailing Edge ◽  
Integral Boundary ◽  
Wide Range ◽  
Boundary Layer Method ◽  
Time Marching ◽  
Flow Through ◽  
Euler Solver ◽  
Profile Loss

A simple numerical method for predicting the profile loss of turbine blades in subsonic and transonic flows is presented. A time marching Euler solver is used to obtain the main flow through the blade passages, the loss due to the surface friction is calculated using an integral boundary layer method, the total mixed out loss is evaluated from the mass flow and momentum balances between the trailing edge plane and an imaginary downstream plane where the flow is uniform. The base pressure acting on the trailing edge of the blade is calculated directly from the inviscid calculation without empirical correlations. The spurious numerical loss in the Euler calculation is separated from the real loss. The rationality of the approach is justified by the agreement of the prediction with a wide range of experimental measurements.

scholarly journals Transonic Cascade Analysis by a Time Marching Method

1985 ◽  
Author(s):  
Francesco Martelli ◽  
Luca Marchi
Keyword(s):  
Transonic Flow ◽  
Computational Speed ◽  
Cascade Analysis ◽  
Two Dimensional Flow ◽  
Time Marching ◽  
Transonic Turbine ◽  
Turbine Cascades ◽  
New Formulation ◽  
Transonic Cascade ◽  
Marching Method

Time marching solutions of transonic flow are widely used for the analysis of turbomachinery cascades. Attempts to increase efficiency, accuracy and computational speed are, at present, the main goal of research in the field of two dimensional flow. The aim of the paper is the presentation of a new pseudo-time dependent method to try to achieve these goals. The method, basic idea and procedure used to develop the new formulation are described and discussed in brief. Some applications of the method to transonic turbine cascades are presented against experimental results. The accuracy and speed of the method is discussed and possibilities for further developments are shown.

SHOCK WAVE INTERACTION NEAR A CYLINDER ALIGNED NORMAL TO A BLUNTED PLATE—PART I: GAS FLOW AND HEAT TRANSFER ON A PLATE NEAR A CYLINDER

2018 ◽  
Vol 49 (2) ◽  
pp. 105-118
Author(s):  
Volf Ya. Borovoy ◽  
Vladimir Evguenyevich Mosharov ◽  
Vladimir Nikolaevich Radchenko ◽  
Arkadii Sergeyevich Skuratov
Keyword(s):  
Heat Transfer ◽  
Shock Wave ◽  
Gas Flow ◽  
Wave Interaction ◽  
Shock Wave Interaction ◽  
Flow And Heat Transfer
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