Heat transfer studies on the interior surfaces of cooled nozzle guide vane in a linear cascade

Experimental and computational heat transfer investigations are reported in the interior side of a nozzle guide vane (NGV) subjected to combined impingement and film cooling. The domain of study is a two dimensional five-vane cascade having four passages. Each vane has a chord length of 228 mm and the pitch distance between the vanes is 200 mm. The vane internal surface is cooled by dry air supplied through the two impingement inserts: The front and the aft. The mass flow through the impingement chamber is varied, for a fixed spacing (H) to jet diameter (d) ratio of 1.2. The surface temperature distributions, at certain l°Cations of the vane interior, are measured by pasting strips of liquid crystal sheets. The vane interior surface temperature distribution is also obtained by computations carried out by using Shear stress transport (SST) k-turbulence model in the ANSY FLUENT-14 flow solver. The computational data are in good agreement with the measured values of temperature. The internal heat transfer coefficients are thence determined along the leading edge and the mid span region from the computational data.