Experimental Investigation of the Three-Dimensional Flow in an Annular Compressor Cascade

1988 ◽  
Vol 110 (4) ◽  
pp. 467-478 ◽  
Author(s):  
H. D. Schulz ◽  
H. D. Gallus
Keyword(s):  
Boundary Layer ◽  
Experimental Investigation ◽  
Three Dimensional ◽  
Suction Side ◽  
Boundary Layer Transition ◽  
Compressor Cascade ◽  
Three Dimensional Flow ◽  
Layer Transition ◽  
Integral Boundary ◽  
Dimensional Flow

A detailed experimental investigation was carried out to examine the influence of blade loading on the three-dimensional flow in an annular compressor cascade. Data were acquired over a range of incidence angles. Included are airfoil and endwall flow visualization, measurement of the static pressure distribution on the flow passage surfaces, and radial-circumferential traverse measurements. The data indicate the formation of a strong vortex near the rear of the blade passage. This vortex transports low-momentum fluid close to the hub toward the blade suction side and seems to be partly responsible for the occurrence of a hub corner stall. The effect of increased loading on the growth of the hub corner stall and its impact on the passage blockage are discussed. Detailed mapping of the blade boundary layer was done to determine the loci of boundary layer transition and flow separation. The data have been compared with results from an integral boundary layer method.

Numerical Simulation of the Boundary Layer Transition in Turbomachinery Flows

2001 ◽  
Author(s):  
Hans Thermann ◽  
Michael Müller ◽  
Reinhard Niehuis
Keyword(s):  
Boundary Layer ◽  
Separated Flow ◽  
Suction Side ◽  
Boundary Layer Transition ◽  
Test Cases ◽  
Compressor Cascade ◽  
Layer Transition ◽  
Transonic Compressor ◽  
Transition Models ◽  
Transition Modeling

The objective of the presented work is to investigate models which simulate boundary layer transition in turbomachinery flows. This study focuses on separated-flow transition. Computations with different algebraic transition models are performed three-dimensionally using an implicit Navier-Stokes flow solver. Two different test cases have been chosen for this investigation: First, a linear transonic compressor cascade, and second an annular subsonic compressor cascade. Both test cases show three-dimensional flow structures with large separations at the side-walls. Additionally, laminar separation bubbles can be observed on the suction and pressure side of the blades of the annular subsonic cascade whereas a shock-induced separation can be found on the suction side of the blades of the linear transonic cascade. Computational results are compared with experiments and the effect of transition modeling is analyzed. It is shown that the prediction of the boundary layer development can be substantially improved compared to fully turbulent computations when algebraic transition models are applied.

scholarly journals Experimental Investigation of Boundary Layer Transition and Turbulence Structures on a Highly Loaded Compressor Cascade

1995 ◽  
Author(s):  
Dirk Wunderwald ◽  
Leonhard Fottner
Keyword(s):  
Boundary Layer ◽  
Suction Side ◽  
Boundary Layer Transition ◽  
Reynolds Stresses ◽  
Flow Conditions ◽  
Compressor Cascade ◽  
Layer Transition ◽  
Engine Operation ◽  
Inlet Flow ◽  
Free Stream Turbulence

Detailed measurements have been performed on a compressor cascade in order to obtain information about the overall performance, the state of the boundary layer, and the topology of turbulent boundary layers. The analysis of profile pressure distributions and wake traverse measurements across the midspan section of the cascade blade provide information on the loss behaviour. Using surface-mounted hot-film gauges on the suction side of the measuring blade different transition phenomena have been investigated under the influence of various inlet flow conditions representative of engine operation. Extensive measurements with 3D-hot-sensor anemometry have been evaluated to show essential features of the turbulent boundary layer. The results point out the dependence of turbulence characteristics, e.g. turbulent kinetic energy distribution and Reynolds stresses, on the inlet flow conditions and the upstream boundary layer development. The influence of free-stream turbulence intensity is discussed and the non-isotropy of the Reynolds normal stresses is presented.

Transition effect on aerodynamic performance of compressor profile

2020 ◽  
Vol 92 (4) ◽  
pp. 611-620
Author(s):  
Ryszard Szwaba ◽  
Piotr Kaczyński ◽  
Piotr Doerffer
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Aerodynamic Performance ◽  
Negative Influence ◽  
Good Choice ◽  
Boundary Layer Transition ◽  
Roughness Height ◽  
Compressor Cascade ◽  
Layer Transition ◽  
Content Type

Purpose The purpose of this paper is to study experimentally the effect of transition and also the roughness height on the flow structure of the shock wave boundary layer interaction in the blades passage of a compressor cascade. Design/methodology/approach A model of a turbine compressor passage was designed and assembled in a transonic wind tunnel. In the experiment, the distributed roughness with different heights and locations was used to induce transition upstream of the shock wave. Findings Recommendation regarding the roughness parameters for the application depends on what is more important as goal, whether the reduction of losses or unsteadiness. In case if more important are the losses reduction, a good choice for the roughness location seems to be the one close to the shock wave position. Research limitations/implications The knowledge gained by this paper will enable the implementation of an effective laminar flow technology for engines in which the interaction of a laminar boundary layer with a shock wave takes place in the propulsion system and causes severe problems. Originality/value The paper focuses on the influence of the boundary layer transition induced by different roughness values and locations on aerodynamic performance of a compressor cascade. Very valuable results were obtained in the roughness application for the boundary layer transition control, demonstrating a positive effect in changing the nature of the interaction and also some negative influence in case of oversized roughness height, which cannot be found in the existing literature.

Numerical simulation of boundary-layer transition and transition control

1989 ◽  
Vol 199 ◽  
pp. 403-440 ◽  
Author(s):  
E. Laurien ◽  
L. Kleiser
Keyword(s):  
Boundary Layer ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Transition Process ◽  
Numerical Results ◽  
Boundary Layer Transition ◽  
Two Dimensional ◽  
Layer Transition ◽  
Longitudinal Vortices ◽  
Tollmien Schlichting

The laminar-turbulent transition process in a parallel boundary-layer with Blasius profile is simulated by numerical integration of the three-dimensional incompressible Navier-Stokes equations using a spectral method. The model of spatially periodic disturbances developing in time is used. Both the classical Klebanoff-type and the subharmonic type of transition are simulated. Maps of the three-dimensional velocity and vorticity fields and visualizations by integrated fluid markers are obtained. The numerical results are compared with experimental measurements and flow visualizations by other authors. Good qualitative and quantitative agreement is found at corresponding stages of development up to the one-spike stage. After the appearance of two-dimensional Tollmien-Schlichting waves of sufficiently large amplitude an increasing three-dimensionality is observed. In particular, a peak-valley structure of the velocity fluctuations, mean longitudinal vortices and sharp spike-like instantaneous velocity signals are formed. The flow field is dominated by a three-dimensional horseshoe vortex system connected with free high-shear layers. Visualizations by time-lines show the formation of A-structures. Our numerical results connect various observations obtained with different experimental techniques. The initial three-dimensional steps of the transition process are consistent with the linear theory of secondary instability. In the later stages nonlinear interactions of the disturbance modes and the production of higher harmonics are essential.We also study the control of transition by local two-dimensional suction and blowing at the wall. It is shown that transition can be delayed or accelerated by superposing disturbances which are out of phase or in phase with oncoming Tollmien-Schlichting instability waves, respectively. Control is only effective if applied at an early, two-dimensional stage of transition. Mean longitudinal vortices remain even after successful control of the fluctuations.

Numerical Study of Wall Influence on Boundary-Layer Transition for Two-Dimensional NACA 16-012 and 4412 Hydrofoil Sections

1990 ◽  
Vol 34 (01) ◽  
pp. 38-47
Author(s):  
R. Latorre ◽  
R. Baubeau
Keyword(s):  
Boundary Layer ◽  
Test Section ◽  
Numerical Study ◽  
Suction Side ◽  
Boundary Layer Separation ◽  
Boundary Layer Transition ◽  
Layer Transition ◽  
Turbulent Separation ◽  
Side Pressure ◽  
Effective Angle

One of the difficulties in hydrofoil model tests is the relatively low Reynolds number of the test piece and the presence of the test section walls. This paper presents the results of systematic calculations of the potential flow field of NA 4412 and NACA 16-012 hydrofoil in a test section with wall-to-chord ratios h/c -1.0. The corresponding boundary-layer calculations using the CERT calculation scheme are presented to show the influence of the nearby walls on shifting the location of the boundary-layer laminar-turbulent separation as well as turbulent separation. By introducing an effective angle of attack, it is possible to obtain close agreement in the calculated and measured suction side pressure distortion as well as the locations of the boundary-layer separation and transition.

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