The use of liquid crystals for the determination of surface temperature distributions in aerodynamics

A thermographic method is described for determining spatial surface temperature distributions, using liquid crystals that change colour with temperature. The method uses a colour video camera, a frame-grabber and two computers for registering and analyzing the digital images. The thesis describes the development of a "hue-saturation-intensity" (HSI) method and calibration technique for carrying out measurements of surface temperature. Some preliminary experiments are described illustrating the application of the method to provide surface temperature distribution and isothermal lines for three-dimension flows associated with heated "wall jet" flows.