In this study, all inverse algorithm based oil the conjugate gradient method is applied to a steady flow over it cascade of rectangular blades to estimate the inlet flow temperature. The objective is to study the difficulties associated with inverse heat convection problems. Therefore, the measurement quantity has been deliberately placed at five different locations over the domain, each of them covered by a unique flow feature. The computation shows that at very low Reynolds number, the accuracy of the inverse method is not affected by the relative position between the estimated and measurement quantities. At a higher Reynolds number, however, the accuracy of the inverse method strongly depends on the relative position between the two quantities. The inverse method only returns satisfactory estimation for sonic cases but not others. (c) 2008 Published by Elsevier Ltd.