Impinging-jet heat transfer via IR thermography
This paper presents an experimental study of convective heat transfer under an impinging jet (Re = 10,000), using non-intrusive infrared thermography to obtain spatially resolved temperature fields.
Method
A MATLAB-based data processing pipeline computes the local heat transfer coefficient field h(x,y) and Nusselt number distributions from energy balance equations. The balance accounts for Joule heating, radiation losses and in-plane conduction, at a spatial resolution of 0.08 mm/pixel with uncertainty around 5%.
Results
The effect of jet-to-plate distance was analysed across H/D = 2–6, showing increasing heat transfer coefficients with increasing H/D (h = 100→120 W/m²K, Nu = 45→55), consistent with jet development theory — the jet has further to develop and arrives more turbulent.
/assets/img/papers/jet-h-maps.pngDesign modifications were evaluated by testing non-axisymmetric rectangular nozzle geometries, achieving enhanced peak heat transfer up to h = 127 W/m²K and demonstrating the impact of nozzle geometry on convective performance.
Radial Nusselt profiles confirmed the expected stagnation peak behaviour and the decay through the wall-jet region.