In turbulence research, the velocity-pressure-gradient tensor in the Reynolds stress transport equation is critical for understanding and modeling of turbulence. Pressure is also of fundamental importance in understanding and modeling of cavitation. Motivated by the lack of experimental tools to measure the instantaneous pressure distribution away from boundaries, the paper introduces a non-intrusive method for simultaneously measuring the instantaneous velocity and pressure distribution over a sample area. The technique utilizes four exposure PIV to measure the distribution of material acceleration, and integrating it to obtain the pressure distribution. If necessary, e.g., for cavitation research, a reference pressure at a single point is also required. Two cameras and perpendicularly polarized Nd:Yag lasers are used for recording four exposures on separate frames. Images 1 and 3 are used for measuring the first velocity distribution, whereas images 2 and 4 give the second velocity map. The material acceleration is calculated from the velocity difference in sample areas shifted relative to each other according to the local velocity. Averaged omni-directional integration of the material acceleration over the entire flow field, while avoiding regions dominated by viscous diffusion, provides the pressure distribution. To improve the accuracy of the acceleration measurement, cross-correlation of the corresponding image correlation maps is implemented in areas with high velocity gradient. Applications of these procedures to synthetic flows show that the standard deviation of the measured instantaneous pressure from the theoretical value is about 2%. The system has been used to measure the instantaneous pressure and velocity distributions of a 2D cavity flow field in a water tunnel. Three pressure transducers mounted at different locations on the wall are being used for comparison and calibration. Detailed measurements of acceleration, vorticity and pressure distributions within the cavity shear layer indicate that the cavity shear layer flow exhibits highly unsteady behavior due to the self-excited oscillation.
Skip Nav Destination
ASME 2004 Heat Transfer/Fluids Engineering Summer Conference
July 11–15, 2004
Charlotte, North Carolina, USA
Conference Sponsors:
- Heat Transfer Division and Fluids Engineering Division
ISBN:
0-7918-4692-X
PROCEEDINGS PAPER
Measurements of Pressure Distribution in a Cavity Flow by Integrating the Material Acceleration Available to Purchase
Xiaofeng Liu,
Xiaofeng Liu
Johns Hopkins University, Baltimore, MD
Search for other works by this author on:
Joseph Katz
Joseph Katz
Johns Hopkins University, Baltimore, MD
Search for other works by this author on:
Xiaofeng Liu
Johns Hopkins University, Baltimore, MD
Joseph Katz
Johns Hopkins University, Baltimore, MD
Paper No:
HT-FED2004-56373, pp. 621-631; 11 pages
Published Online:
February 24, 2009
Citation
Liu, X, & Katz, J. "Measurements of Pressure Distribution in a Cavity Flow by Integrating the Material Acceleration." Proceedings of the ASME 2004 Heat Transfer/Fluids Engineering Summer Conference. Volume 3. Charlotte, North Carolina, USA. July 11–15, 2004. pp. 621-631. ASME. https://doi.org/10.1115/HT-FED2004-56373
Download citation file:
16
Views
Related Proceedings Papers
Related Articles
Erratum: “Numerical Investigations of Pressure Distribution Inside a Ventilated Supercavity” [ASME J. Fluids Eng., 2017, 139 (2), p. 021301; DOI: 10.1115/1.4035027 ]
J. Fluids Eng (December,2018)
Numerical Study of Sheet Cavitation Breakoff Phenomenon on a Cascade Hydrofoil
J. Fluids Eng (July,2003)
Related Chapters
Experimental Characterization of a Cavitating Orifice
Proceedings of the 10th International Symposium on Cavitation (CAV2018)
Cavitating Structures at Inception in Turbulent Shear Flow
Proceedings of the 10th International Symposium on Cavitation (CAV2018)
An Experimental Study of Unsteady Behaviour of Cavity Flow Over a 2-D Wall-Mounted Fence
Proceedings of the 10th International Symposium on Cavitation (CAV2018)