Unsteady Three-Dimensional Turbine Aerodynamics

1983 ◽  
Vol 105 (2) ◽  
pp. 322-331 ◽  
Author(s):  
H. D. Joslyn ◽  
R. P. Dring ◽  
O. P. Sharma
Keyword(s):  
Total Pressure ◽  
Velocity Vector ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
High Response ◽  
Phase Lock ◽  
Reduced Data ◽  
Made In ◽  
Periodic Changes

High response aerodynamic measurements were made in a large-scale, axial, flow turbine model to study the unsteadiness and three dimensionality of the flow. High response velocity vector and total pressure data were acquired. A comparison was made of the results of phase lock averaging both raw and reduced data (voltages and velocities). The velocity vector measurements showed that there were strong radial flows present as well as significant periodic changes in the flow field due to relative rotor and vane positions. Random, periodic, and total unsteadiness levels were computed from the instantaneous and phase-lock-averaged velocity data. Time-averaged data were compared with an inviscid two-dimensional calculation. A comparison was also made of time-averaged total pressure measurements obtained from high-response and low-response (steady-state) probes.

Unsteady Three-Dimensional Turbine Aerodynamics

1982 ◽  
Author(s):  
H. D. Joslyn ◽  
R. P. Dring ◽  
O. P. Sharma
Keyword(s):  
Total Pressure ◽  
Velocity Vector ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
High Response ◽  
Phase Lock ◽  
Reduced Data ◽  
Made In ◽  
Periodic Changes

High response aerodynamic measurements were made in a large scale, axial, flow turbine model to study the unsteadiness and three dimensionality of the flow. High response velocity vector and total pressure data were acquired. A comparison was made of the results of phase lock, averaging both raw and reduced data (voltages and velocities). The velocity vector measurements showed that there were strong radial flows present as well as significant periodic changes in the flow field due to relative rotor and vane positions. Random, periodic, and total unsteadiness levels were computed from the instantaneous and phase lock averaged velocity data. Time averaged data were compared with an inviscid two-dimensional calculation. A comparison was also made of time averaged total pressure measurements obtained from high response and low response (steady-state) probes.

Unsteady Three-Dimensional Analysis of Inlet Distortion in a Transonic Fan

2006 ◽  
Author(s):  
Peng Sun ◽  
Guotal Feng
Keyword(s):  
Shock Wave ◽  
Total Pressure ◽  
Large Scale ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Inlet Distortion ◽  
Flow Loss ◽  
Large Scale Vortex ◽  
Total Temperature ◽  
Transonic Fan

A time-accurate three-dimensional Navier-Stokes solver of the unsteady flow field in a transonic fan was carried out using "Fluent-parallel" in a parallel supercomputer. The numerical simulation focused on a transonic fan with inlet square wave total pressure distortion and the analysis of result consisted of three aspects. The first was about inlet parameters redistribution and outlet total temperature distortion induced by inlet total pressure distortion. The pattern and causation of flow loss caused by pressure distortion in rotor were analyzed secondly. It was found that the influence of distortion was different at different radial positions. In hub area, transportation-loss and mixing-loss were the main loss patterns. Distortion not only complicated them but enhanced them. Especially in stator, inlet total pressure distortion induced large-scale vortex, which produced backflow and increased the loss. While in casing area, distortion changed the format of shock wave and increased the shock loss. Finally, the format of shock wave and the hysteresis of rotor to distortion were analyzed in detail.

An Experimental Investigation of the Flow Through an Axial-Flow Pump

1995 ◽  
Vol 117 (3) ◽  
pp. 485-490 ◽  
Author(s):  
W. C. Zierke ◽  
W. A. Straka ◽  
P. D. Taylor
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Fast Response ◽  
Complex Flow ◽  
Penn State ◽  
Response Pressure ◽  
Axial Flow Pump ◽  
Scale Experiment ◽  
High Reynolds

The high Reynolds number pump (HIREP) facility at ARL Penn State has been used to perform a low-speed, large-scale experiment of the incompressible flow of water through a two-blade-row turbomachine. The objectives of this experiment were to provide a database for comparison with three-dimensional, turbulent flow computations, to evaluate engineering models, and to improve our physical understanding of many of the phenomena involved in this complex flow field. This summary paper briefly describes the experimental facility, as well as the experimental techniques—such as flow visualization, static-pressure measurements, laser Doppler velocimetry, and both slow- and fast-response pressure probes. Then, proceeding from the inlet to the exit of the pump, the paper presents highlights of experimental measurements and data analysis, giving examples of measured physical phenomena such as endwall boundary layers, separation regions, wakes, and secondary vortical structures. In conclusion, this paper provides a synopsis of a well-controlled, larger scope experiment that should prove helpful to those who wish to use the database.

Calculation of Fluid Motion in Axial Flow Turbomachines

1968 ◽  
Author(s):  
D. J. L. Smith ◽  
J. F. Barnes
Keyword(s):  
Experimental Work ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Axial Flow ◽  
Streamline Curvature ◽  
Through Flow ◽  
Loss Distributions ◽  
The Matrix ◽  
Made In

In the last few years considerable progress has been made in calculating the three-dimensional flows through turbomachines. The two methods which appear to be widely used are what have come to be known as the “Streamline Curvature” and the “Matrix Through Flow” methods. At the National Gas Turbine Establishment, these advanced methods have been applied to existing turbomachines and this paper presents some of the calculated and experimental results for four axial flow machines. By making use of fairly simple loss distributions it has been found that these methods can assist towards the understanding of observed phenomena and, in the case of the axial compressor, they offer some prospect of being able to calculate the onset of surge. Also included is a brief report of work in progress to generate a computer program for the solution of the compressible velocity distribution around the surfaces of turbomachine blades, together with an indication of possible future experimental work.

Three-Dimensional Turbulent Flow in the Tip Region of an Axial Compressor Rotor Passage at a Near Stall Condition

2001 ◽  
Author(s):  
Hongwei Ma ◽  
Haokang Jiang
Keyword(s):  
Turbulent Flow ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Leading Edge ◽  
Rotating Stall ◽  
Suction Surface ◽  
Tip Leakage Vortex ◽  
Tip Leakage ◽  
Compressor Rotor

This paper presents an experimental study of the three-dimensional turbulent flow field in the tip region of an axial flow compressor rotor passage at a near stall condition. The investigation was conducted in a low-speed large-scale compressor using a 3-component Laser Doppler Velocimetry and a high frequency pressure transducer. The measurement results indicate that a tip leakage vortex is produced very close to the leading edge, and becomes the strongest at about 10% axial chord from the leading edge. Breakdown of the vortex periodically occurs at about 1/3 chord, causing very strong turbulence in the radial direction. Flow separation happens on the tip suction surface at about half chord, prompting the corner vortex migrating toward the pressure side. Tangential migration of the low-energy fluids results in substantial flow blockage and turbulence in the rear of a rotor passage. Unsteady interactions among the tip leakage vortex, the separated vortex and the corner flow should contribute to the inception of the rotating stall in a compressor.

Computation and Measurement of the Flow in Axial Flow Fans With Skewed Blades

1999 ◽  
Vol 121 (1) ◽  
pp. 59-66 ◽  
Author(s):  
M. G. Beiler ◽  
T. H. Carolus
Keyword(s):  
Total Pressure ◽  
Design Method ◽  
Power Level ◽  
Three Dimensional ◽  
Axial Flow ◽  
Pressure Rise ◽  
Fast Response ◽  
Test Facility ◽  
Navier Stokes ◽  
Pressure Probe

A numerical analysis of the flow in axial flow fans with skewed blades has been conducted to study the three-dimensional flow phenomena pertaining to this type of blade shape. The particular fans have a low pressure rise and are designed without stator. Initial studies focused on blades skewed in the circumferential direction, followed by investigations of blades swept in the direction of the blade chord. A Navier–Stokes code was used to investigate the flow. The simulation results of several fans were validated experimentally. The three-dimensional velocity field was measured in the fixed frame of reference with a triple sensor hot-film probe. Total pressure distribution measurements were performed with a fast response total pressure probe. The results were analyzed, leading to a design method for fans with swept blades. Forward swept fans designed accordingly exhibited good aerodynamic performance. The sound power level, measured on an acoustic fan test facility, improved.

A Trace Gas Technique to Study Mixing in a Turbine Stage

1988 ◽  
Vol 110 (1) ◽  
pp. 38-43 ◽  
Author(s):  
H. D. Joslyn ◽  
R. P. Dring
Keyword(s):  
Temperature Profile ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Surface Flow ◽  
Trace Gas ◽  
Inlet Temperature ◽  
Turbine Stage ◽  
Radial Temperature ◽  
Gas Concentration

An experimental technique to study mixing in a turbine stage is demonstrated. An axisymmetric, radial temperature profile at the inlet to the first stator of a large-scale, low-speed, single-stage, axial flow turbine model is simulated with a radial trace gas concentration distribution. Mixing or redistribution of the inlet profile by three-dimensional aerodynamic mechanisms (other than temperature-driven mechanisms) is determined from trace gas concentration measurements made in both the stationary and rotating frames of reference at various locations through the turbine. The trace gas concentration contours generated are consistent with flow pitch angle measurements made downstream of the first stator and with surface flow visualization on the rotor airfoil and the hub endwall. It is demonstrated that this trace gas technique is well suited to quantify many aspects of the redistribution and diffusion of an inlet temperature profile as it is convected through a turbine stage.

Measurement and Calculation of Turbine Cascade Endwall Pressure and Shear Stress

2005 ◽  
Vol 128 (2) ◽  
pp. 232-239 ◽  
Author(s):  
Brian M. Holley ◽  
Sandor Becz ◽  
Lee S. Langston
Keyword(s):  
Shear Stress ◽  
Skin Friction ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Predictive Ability ◽  
Wall Friction ◽  
Friction Coefficients ◽  
Local Skin ◽  
Aerodynamic Loss

The complex three-dimensional fluid flow on the endwall in an axial flow turbine blade or vane passage has been extensively investigated and reported on in turbomachinery literature. The aerodynamic loss producing mechanisms associated with the endwall flow are still not fully understood or quantitatively predictable. To better quantify wall friction contributions to endwall aerodynamic loss, low Mach number wind tunnel measurement of skin friction coefficients have been made on one endwall of a large scale cascade of high pressure turbine airfoils, at engine operating Reynolds numbers. Concurrently, predictive calculations of the endwall flow shear stress have been made using a computational fluid dynamics (CFD) code. Use of the oil film interferometry skin friction technique is described and applied to the endwall, to measure local skin friction coefficients and shear stress directions on the endwall. These are correlated with previously reported measured local endwall pressure gradients. The experimental results are discussed and compared to the CFD calculations, to answer questions concerning endwall aerodynamic loss predictive ability.

A Method for Predicting Compressor Cascade Total Pressure Losses When the Inlet Relative Mach Number Is Greater Than Unity

1971 ◽  
Vol 93 (1) ◽  
pp. 119-124 ◽  
Author(s):  
R. L. Balzer
Keyword(s):  
Total Pressure ◽  
Axial Flow ◽  
Shock Formation ◽  
Flow Conditions ◽  
Compressor Cascade ◽  
Viscous Effects ◽  
Pressure Losses ◽  
The Past ◽  
Flow Compressor ◽  
Made In

During the last few years, considerable progress has been made in predicting the total pressure losses from viscous effects for axial-flow compressor cascades. With the advent of the transonic and the supersonic stage, another pressure loss generating mechanism was introduced—the shock wave. Various methods have been published over the past few years accounting for the pressure losses associated with the shock formation, but of those reviewed by this author, none of them has been consistently successful for predicting the losses at other than design conditions. This paper develops a method which has given consistent success at all flow conditions for compressors with subsonic axial and supersonic relative velocities.

scholarly journals Negative Incidence Flow Over a Turbine Rotor Blade

1983 ◽  
Author(s):  
H. David Joslyn ◽  
Robert P. Dring
Keyword(s):  
Gas Turbines ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Turbine Rotor ◽  
Surface Flow ◽  
Separated Flows ◽  
Turbine Rotor Blade ◽  
Pressure Surface ◽  
Pressure Distributions

The operation of variable cycle gas turbines at negative incidence can result in highly three dimensional separated flows on the turbine rotor pressure surface. These flows can impact both performance and durability. The present program was conducted to experimentally study the behavior of surface flow on a large scale axial flow turbine rotor with incidence varying up to and including negative incidence separation. Fullspan pressure distributions and surface flow visualization were acquired over a range of incidence. The data indicate that at large negative incidence, pressure surface separation occurred and extended to 60 percent chord at midspan. These separated flows were simulated at midspan by applying potential flow theory to match the measured pressure distributions.

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