07 - Systems, Subsystems and Equipment
NUMERICAL METHOD FOR DESIGNING AND MODELING AN EXHAUST CLUSTER FOR A SMALL TURBOJET ENGINE TEST CELL
T.-G. Nguyen¹, Q.-H. Nghiem¹, P.-M. Nguyen¹; ¹Viettel Aerospace Institute, Vietnam
This paper describes the process of designing, modeling, and simulating a jet engine test cell’s exhaust cluster including an augmentor tube, a blast bucket, a deflector cone, and a square-cross-section exhaust stack. This system is intended for testing a small and uncooled turbojet engine at sea level condition with exhausted gas temperature (EGT) of around 700°C. The studying method used in this research is Computational Fluid Dynamics (CFD). The design target is to dilute the engine’s hot exhaust gas by induced air via an augmentor tube to the extent that allows installation of supervising camera at the nose of a deflector cone i.e. 150 oC. After that, a deflector cone and a blast basket are used to divert and decelerate the direction of now-cooled exhaust gas into an exhaust stack. By introduction of a dump region design between a deflector cone and a blast bucket, it is discovered to address the shortcomings of published systems so that the high velocity jets are no longer blown against an exhaust stack’s end wall. This design feature promotes mixing between high and low velocity jets inside an exhaust stack, exploiting better exhaust stack’s space to offer more slowed down, more uniform flow field before discharging to ambient environment.