Numerical Investigation using Computational Fluid Dynamics to Improve Thermal Efficiency of Exhaust Manifolds in Hot Air Sterilization Systems

This computational fluid dynamics study examined the exhaust manifold of a hot air sterilizer. The exhaust manifold's thermal and flow properties at varied engine rpm were studied to optimize the temperature profile, pressure regulation, and exhaust gas velocity. Optimizing sterilizer efficiency and heat control requires this evaluation. This study simulated Computational Fluid Dynamics (CFD) using Ansys 2023 (Student Version). Boundary conditions and a structured mesh were employed to construct the manifold for engine speeds ranging from 750 to 2000 rpm. The exhaust manifold heat transfer simulations utilized a k-ε turbulence model to account for flow dynamics accurately. Recorded and assessed exhaust gas velocities, temperatures, and pressure contours to assess system performance. The exhaust flow velocity and pressure increased substantially with engine speed up to 2000 rpm, when the engine reached 70 m/s and more than 2 kPa. The temperature profile showed considerable cooling with a maximum wall temperature of 444°C at the highest engine speed. The study found that manifold geometry, form, and material choice are crucial in limiting back pressure and heat loads at higher engine rpm. Finally, mechanical stasis zones become observable at lower flow velocities, which may help refine the design. A well-designed exhaust manifold is necessary to prevent overheating and ensure optimal gas flow. Materials like steel, which dissipate heat, are key to gadget longevity. The study's findings can enhance the performance and reliability of hot air sterilizers in high-temperature environments.