Reynolds number effect on the heat transfer mechanisms in aircraft hot air anti-ice system.






The primary means of preventing ice formation on wings and engine inlets for modern commercial transport aircraft is by extracting hot air from the compressor and blowing it on the inside surface of the leading edge through small holes drilled in the so-called piccolo tube system. A critical aspect in the design of such system is the prediction of heat transfer of the impinging jets from the piccolo tube. The correct evaluation of the heat transfer rate in such devices is of great interest to optimize both the anti-icing performance and the hot air bleeding from the high-pressure compressor. The history of research in the anti-icing area is rather narrow. A review of the literature reveals that only few experimental and theoretical/numerical studies have been carried out to study the heat transfer and flow in the internal hot-air region. There are some experimental and numerical studies that developed correlations for the average Nusselt number. However, most of the research was performed using a single jet or a group of jets impinging on a flat slat, which is different from the jet impingement on concave surfaces, as the inside surface of a wing. Therefore, the objective of the present work is use the commercial CFD software FLUENT to perform a parametric study of the jet impingement on concave surfaces. The main goal is determine the effect of the Reynolds number on the heat transfer process. At the end of the work, a correlation for the average Nusselt number which account for the Reynolds number is presented.