Design of air cycle machine with a radial turbine and a radial compressor and computational fluid dynamics analysis

The climatization process is still a phenomenon of great importance from the past to the present. Various engineering activities are carried out in many similar areas, from cooling electronic equipment to keeping commercial passenger aircraft and automotive cabins within the defined comfort temperature range. Especially in aerial platforms, the cooling process takes a critical role. Conventional cooling systems, which contain a vapor compression cycle, are rarely used on aerial platforms at present. Air cycle cooling systems have many advantages about air conditioning for aerial platforms. Low power consumption, low weight, ease of maintenance and repair are important advantages of Air Cycle Machines (ACM). Using air as a coolant which is a safe and clean fluid instead of ozone-depleting gases is an additional and important advantage of an ACM. Air cycle machines are the most essential component in air cycle cooling systems. Air cycle machines have many different configurations according to the requirements of aerial platforms such as flight mission profiles, required cooling capacity, pressurization and humidity control. Within the scope of present studies, research was carried out on the cooling of the under-wing pod of fighter jets with a ram powered reverse bootstrap, 2-wheel, air cycle machines. A radial turbine and compressor have been designed for cooling the external pod located under the wing of aerial platforms. First, conceptual design calculation were carried out for a preleminery design of ACM. Three-dimensional blade geometries were obtained by providing input to the ANSYS BladeGen program through the inputs obtained for these calculations and the outputs obtained with ANSYS Vista RTD (Radial Turbine Design) and CCD (Centrifugal Compressor Design). Adding the guidevane geometries to the blade geometries, single-stage (one-blade) three dimensional Computational Fluid Dynamics (CFD) analyzes were performed. In order to carry out more comprehensive numerical studies, three-dimensional Computational Fluid Dynamics analyzes including all system components were run. The geometry used in CFD analysis, which includes all system components, includes turbine and compressor rotors and volutes, guide blade profile and piping. Three Dimensional Computational Fluid Dynamics (CFD) analysis were performed for the detailed design of experiment (DOE). Within the framework mesh independence and turbulence model studies were carried out. CFD compuations were performed using ANSYS CFX solver. Tests were performed on the designed ACM installed at ANOVA ARGE A.Ş. and results were compared with the 3D CFD predictions.