PIV에 의한 압력장 추정 개선방안에 관한 연구

Abstract

PIV(Particle Image Velocimetry) is a very powerful measuring technique. By recording two sequential particle images separated by a short time interval, the instantaneous velocity distribution of the whole flow field can be determined by the cross-correlation analysis of the two sequential images.

A staggered grid momentum equation and Poisson’s equation which are able to produce correct pressure distribution directly if correct velocities are given, is proposed to solve the pressure distribution for PIV experiments. The proposed pressure equation solvers are first calibrated with a two-dimensional wakes around a cylinder. Poisson’s equation pressure field solved is realistic and accurate then momentum equation pressure field.

Simultaneous measurement system for the pressure field and the velocity field has been constructed. The reference pressure has been measured simultaneously when the PIV measurements have been carried out. The measurement region is the near field of a square bluff body. The pressure fields have been calculated by using the velocity field obtained by the PIV system and the reference pressure measured simultaneously at a reference point. It has been shown that the v velocity components influences the pressure fluctuations. In rear side, it has been shown that the pressure profiles show similar pattern with those of v component. Using the measured data, we obtain the normalized pressure field.