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In recent years Thermochroniic Liquid Crystals (TLC) have been successfully used in non-intrusive heat transfer and fluid mechanics studies. Thin coatings of TLC's at surfaces is utilised to obtain detailed heat transfer data of steady or transient process. Application of TLC tracers allows instantaneous measurement ofthe temperature and velocity fields for two-dimsionaI cross-section of flow. Computerised flow visualisatñi tethniques allow automatic quantification of temperature of the analysed surface or the visualized flow cross-section. Here we describe our experience in applying the method to selected problems studied in our laboratory. They include modeling flow configurations in the differentially heated inclined cavity with vertical temperature gradient simulating up-slope flow as well as thermal convection under freezing surface. The main aim ofthese experimental models is to generate reliable experimental database en velocity and temperature fields for specific flow. The methods are based on computerised tme-colour analysis of digital images for temperature measurements and modified Particle Image Velocimetry and Thermometry (P1VT) used to obtain the flow field velocity.