International Journal of Innovative Research in Computer Science and Technology (IJIRCST) ISSN (Online): 2347-5552, Volume-13, Issue-3, May 2025 https:/doi.org/10.55524/ijircst.2025.13.3.24 Article ID IJIRE-1404, Pages 162-178 www.ijircst.org Innovative Research Publication 162 Multi-Regime CFD Optimization of Diverter-less Supersonic Intake Bump Geometry for Enhanced Engine Pressure Recovery Muhammad Ali 1 , Haroon Saqlain Khan 2 , Mudasir Ghafoor 3 , and Saad Mujtaba 4 1 Graduate Researcher, Department of Mechanical and Materials Engineering, Western University, Canada 2 Graduate Researcher, Department of Materials Engineering, School of Chemicals & Materials Engineering, National, University of Science & Technology, Pakistan. 3 Graduate Researcher, Department of Aerospace, College of Aeronautical Engineering (CAE), National University of Science & Technology, Pakistan. 4 Independent Researcher, Aerospace Engineering, Istanbul, Turkey Correspondence should be addressed to Muhammad Ali Received 19 April 2025; Revised 3 May 2025; Accepted 18 May 2025 Copyright © 2025 Made Muhammad Ali et al. This is an open-access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT- Aircraft intake plays a vital role in overall performance of the aircraft. Purpose of intake is to supply less turbulent and smooth flow to the engine. It must provide maximum pressure recovery for a wide range of operating conditions. Conventional ramp intakes have been used in many older and few modern fighter aircraft (F4 Phantom II, Mig 21, Mig 27, Mirage 2000 & F-14 Tomcat). However, DSI (Diverter Less Supersonic Intake) were used in modern aircraft (JF -17 Block 3, F- 35 & J - 20). Weight, complexity & maintenance cost can be reduced using DSI compared in comparison to the conventional intake. Furthermore, DSI provides higher pressure recovery, lesser boundary layer & less complex geometry. The aim of this research is to model different bump configurations and carry out their CFD analysis in order to establish high performing configuration of DSI air intakes at subsonic & supersonic regimes. Four bump configurations named as smaller, softer, blunter and original bump were modelled in ANSYS at three different speed regimes (Mach No 0.6, 0.95 & 1.5) & comparison was drawn for each type of DSI bump configuration & it was found that pressure recovery of DSI of all four configuration is approximately same in subsonic regions whereas for transonic regime (Mach 0.95) DSI smaller has highest pressure recovery value of 0.868 & supersonic regime bump original has highest pressure recovery value of 0.779. This shows that smaller & smoother bump intake configuration will provide maximum pressure recovery and its position into the air intake is crucial for the pressure recovery. KEYWORDS- CFD, Supersonic Intake, Bump Geometry,Engine Pressure Recovery I. INTRODUCTION Primary function of the air intakes is to ensure smooth flow to the engine despite of air approaching the aircraft from direction other than straight ahead. Normally the design point of the compressor is set at about half of the speed of sound (M=0.5) hence the flow has to accelerate at flight speed lower than this (M<0.5) to match the design point. In the very same way flow has to decelerates at flight speed higher than the design point (M>0.5). Due to these reasons the internal profile of the inlet duct has to accommodate both accelerating and decelerating flows without any undue losses. [1]. The design of subsonic inlet duct is somewhat easier than supersonic aircraft. The reason is that in subsonic aircraft, the inlet faces only subsonic regime and the phenomenon of shock waves and distortion are neglected completely. The design of the supersonic inlet is quite complex and time consuming keeping in view the concept of shock waves generation. In supersonic aircraft, the inlets have different features which exploit the process of shock wave generation to slow down the flow velocity. The air slows down from supersonic to subsonic through shock waves and then from subsonic to engine design point through the inlet duct (Diffuser). A particular system of inlet is chosen keeping in view different constraint such as type of aircraft, cost, time, and operational needs to minimize frictional and shockwaves losses which in turn maximizes the pressure recovery at the compressor. A good intake design is characterized by providing high pressure recovery and low distortion. Therefore, it is essential to divert as much of the boundary layer as possible since it is a factor which affect the quality of the airflow. Pressure recovery is defined as the ratio of total pressure at the engine face and intake face. In other words, it is the average total pressure at the engine face, Aerodynamic Interface Plane (AIP) divided by the free stream total pressure. For engines that are integrated with the body, for example on fighter aircraft, the airflow is travelling along the body of the aircraft before it reaches the air intake. A boundary layer builds up along the body which is not desirable, especially in the part of the flow that supplies the engines. Thus, in order to reduce the boundary layer thickness of air flow intake towards the air intakes the flow separation along with the body of aircraft from nose till the air intakes is requires to be optimized or the air intakes are required to be designed in a shape to cater for this flow separation and maximize the pressure recovery at the engine compressor. As shown in figure 1 the pressure recovery is reduced because of this boundary