Surface oil flow technique and liquid crystal thermography for flow visualization in impulse,wind tunnels

This paper describes flow visualization techniques employing surface oil flow and liquid crystal thermography suitable for use in impulse wind tunnels. High spatial resolution photographs of oil flow patterns and liquid crystal thermograms have been obtained within test times ranging from 7 to 500 ms and have been shown to be very useful for revealing the detailed features of 3-D separated flow. The results from oil flow patterns, liquid crystal thermograms, schlieren photographs and heat flux measurements are shown to be in good agreement.