Computatıonal Studıes On The Thermo-Hydraulıc Performance Of Dıfferent Pıpe Geometrıes Of Compact Tubular Aır To Aır Heat Exchangers Used In Low Bypass Ratıo Turbofan Engınes

Abstract

In this research paper, the thermo-hydraulic performances of the different shapes of the pipes that can be used in the compact air to air heat exchangers of the gas turbine engines have been studied. The standard design/control design has been taken as the cylindrical U bend pipe of diameter 6mm, having a length of 726mm. Three different elliptical pipes of different eccentricities but having equivalent areas are designed to check if the change in design is able to improve the heat transfer characteristics of the heat exchanger, while reducing the pressure losses of the cooling gases. In addition to these two geometrical shapes of the pipes, a new design of pipe which combines the geometries of both the models has been put forth in this paper and its performance has also been studied computationally. The computational calculations are performed using ANSYS CFX. The change in temperature of the hot gases inside the pipes are measured in CFX Post and the effect of the pipe geometry on the pressure drop in the cooling air on the outside of the pipes have also been tabulated and studied.