Personal computer (PC) based image processing applied to fluid mechanics researchA PC based image processing system was employed to determine the instantaneous velocity field of a two-dimensional unsteady flow. The flow was visualized using a suspension of seeding particles in water, and a laser sheet for illumination. With a finite time exposure, the particle motion was captured on a photograph as a pattern of streaks. The streak pattern was digitized and processsed using various imaging operations, including contrast manipulation, noise cleaning, filtering, statistical differencing, and thresholding. Information concerning the velocity was extracted from the enhanced image by measuring the length and orientation of the individual streaks. The fluid velocities deduced from the randomly distributed particle streaks were interpolated to obtain velocities at uniform grid points. For the interpolation a simple convolution technique with an adaptive Gaussian window was used. The results are compared with a numerical prediction by a Navier-Stokes commputation.
Document ID
19880064963
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Cho, Y.-C. (NASA Ames Research Center Moffett Field, CA, United States)
Mclachlan, B. G. (NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1987
Subject Category
Fluid Mechanics And Heat Transfer
Meeting Information
Meeting: Applications of digital image processing X