Identification of boundary layer structures by unsteady surface pressure measurements

2022 ◽  
Author(s):  
Laura Botero ◽  
Eki Liptiay ◽  
Cornelis H. Venner ◽  
Leandro D. de Santana
Keyword(s):  
Boundary Layer ◽  
Surface Pressure ◽  
Pressure Measurements ◽  
Layer Structures ◽  
Unsteady Surface Pressure

Surface pressure measurements in shock wave/boundary-layer interactions

1997 ◽  
Vol 11 (2) ◽  
pp. 164-172
Author(s):  
Yeol Lee ◽  
Sanjay Garg ◽  
Gary S. Settles
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Surface Pressure ◽  
Pressure Measurements ◽  
Wave Boundary Layer ◽  
Wave Boundary

Well Resolved Wall Pressure Measurements in a High Reynolds Number Turbulent Boundary Layer

2004 ◽  
Author(s):  
Brendan F. Perkins
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Turbulent Boundary Layer ◽  
Surface Pressure ◽  
High Reynolds Number ◽  
Wall Pressure ◽  
Pressure Measurements ◽  
Boundary Layer Turbulence ◽  
High Reynolds ◽  
Salt Playa

In order to better understand boundary layer turbulence at high Reynolds number, the fluctuating wall pressure was measured within the turbulent boundary layer that forms over the salt playa of Utah’s west desert. Pressure measurements simultaneously acquired from an array of nine microphones were analyzed and interpreted. The wall pressure intensity was computed and compared with low Reynolds number data. This analysis indicated that the variance in wall pressure increases logarithmically with Reynolds number. Computed autocorrelations provide evidence for a hierarchy of surface pressure producing scales. Space-time correlations are used to compute broadband convection velocities. The convection velocity data indicate an increasing value for larger sensor separations. To the author’s knowledge, the pressure measurements are the highest Reynolds number, well resolved measurements of fluctuating surface pressure to date.

Steady and Unsteady Surface Pressure Distributions Around Rectangular Prisms With Sharp Edges at Reynolds Number Up to 2.5×106

2006 ◽  
Author(s):  
Annick D’Auteuil ◽  
Guy L. Larose
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Surface Pressure ◽  
Angle Of Attack ◽  
Pressure Measurements ◽  
Oncoming Flow ◽  
Pressure Distributions ◽  
Unsteady Surface Pressure ◽  
Sharp Edges ◽  
Flow Reattachment

The commonly-held assumption that the aerodynamics of rectangular prisms with sharp edges are insensitive to Reynolds number is shown to have limitations. Flow reattachment on the top and/or bottom of the prisms can be related to Reynolds number, Re. Steady and unsteady surface pressure measurements were carried out on nine different rectangular prisms for Re from 0.3×106 to 2.5×106 at several angles of attack, in smooth and turbulent flow. It was observed that the reattachment was dependent on parameters such as fineness ratio, edge treatment, angle of attack, turbulence of the oncoming flow and Reynolds number. Permanent reattachment occurred for prisms with fineness ratio of 4 and fluctuating reattachment took place for rectangular prisms with fineness ratio as low as 2.

Influence of Clocking and Vane/Blade Spacing on the Unsteady Surface Pressure Loading for a Modern Stage and One-Half Transonic Turbine

2003 ◽  
Author(s):  
C. W. Haldeman ◽  
M. L. Krumanaker ◽  
M. G. Dunn
Keyword(s):  
Fundamental Frequency ◽  
Surface Pressure ◽  
Pressure Measurements ◽  
Pressure Loading ◽  
Unsteady Pressure ◽  
Spacing Effects ◽  
Unsteady Surface Pressure ◽  
Transonic Turbine ◽  
Vane Clocking ◽  
Experimental Effort

This paper describes pressure measurements obtained for a modern one and one-half stage turbine. As part of the experimental effort, the position of the HPT vane was clocked relative to the downstream LPT vane to determine the influence of vane clocking on both the steady and unsteady pressure loadings on the LPT vane and the HPT blade. In addition, the axial location of the HPT vane relative to the HPT blade was changed to investigate the combined influence of vane/blade spacing and clocking on the unsteady pressure loading. Time-averaged and time-accurate surface-pressure results are presented for several spanwise locations on the vanes and blade. Results were obtained at four different HPT vane-clocking positions and at two different vane/blade axial spacings for three (of the four) clocking positions. For time-averaged results, the effect of clocking is small on the HPT blade and vane. The influence of clocking on the transition ducts and the LPT vane is slightly greater (on the order of ±1%). Reduced HPT vane/blade spacing has a larger effect than clocking on the HPT vanes and blades (±3%) depending upon the particular surface. Examining the data at blade passing and the first fundamental frequency, the effect of spacing does not produce a dramatic influence on the relative changes that occur between clocking positions. The results demonstrate that clocking and spacing effects on the surface pressure loading are very complex and may introduce problems if the results of measurements or analysis made at one span or location in the machine are extrapolated to other sections.

Unsteady Pressures on the Surface of a Ship Hull

2007 ◽  
Author(s):  
Michael Goody ◽  
Theodore Farabee ◽  
Yu-Tai Lee
Keyword(s):  
Boundary Layer ◽  
Surface Pressure ◽  
Pressure Measurement ◽  
Navier Stokes ◽  
Stream Velocity ◽  
Low Frequencies ◽  
Bow Wave ◽  
Lower Reynolds Number ◽  
Unsteady Surface Pressure ◽  
Layer Flow

The unsteady surface pressures caused by turbulent boundary layer flow are a source of sound and vibration. Unsteady surface pressure measurements at locations distributed on the surface of a ship model hull were carried out in order to characterize this source. The pressure measurement locations were distributed over the hull surface from 15% to 70% of the model length. There were several additional pressure measurement locations on the hull surface adjacent to the bow wave. The measurements were performed in the David Taylor Model Basin. The surface pressure spectra collapse to a single curve when scaled by canonical boundary layer variables at measurement locations aft of the bow wave. Additionally, measurements at several of these locations indicate that the pressure sources are convected at 50% to 80% of the free-stream velocity. Both of these observations are similar to equilibrium turbulent boundary layers. The measured surface pressure spectra compare well to predictions done using an empirical model that is based on historical, equilibrium, surface pressure spectra. At low frequencies, the measured surface pressure spectra also compare well to prediction done at lower Reynolds number using a Reynolds-Averged Navier-Stokes Statistical Model.

Wake and Unsteady Surface-Pressure Measurements on an SUV with Rear-End Extensions

2015 ◽  
Author(s):  
Lennert Sterken ◽  
Simone Sebben ◽  
Lennart Lofdahl ◽  
Tim Walker ◽  
Thies Wölken
Keyword(s):  
Surface Pressure ◽  
Pressure Measurements ◽  
Unsteady Surface Pressure
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