Liquid crystal thermography (LCT) has been widely used for the determinatio
n of surface heat transfer distribution. However, this technique is sensiti
ve to illumination and viewing angle and therefore limited to surfaces with
only slight curvature. A liquid crystal calibration technique using true-c
olour image processing system has now been developed to alleviate the effec
t of viewing angle on oblique/curved surfaces. Application of the calibrati
on and transient liquid crystal thermographic techniques and uncertainty an
alysis to a heated air slot jet impinging on a semi-cylindrical convex surf
ace has been demonstrated. It is shown that the local heat transfer coeffic
ient may be overestimated by up to 39.1% at a viewing angle of 69 degrees f
rom the normal under test conditions. However, the overall uncertainty in h
eat transfer coefficient can be significantly reduced from the maximum valu
e of 36.3% to within 11.1%;, by using the implemented viewing calibration t
echnique. (C) 2001 Elsevier Science Ltd. All rights reserved.