A fundamental numerical study on impinging annular jets

• Main Author: Li, Xun
• Other Authors: New Tze How, Daniel
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Mechanical engineering::Fluid mechanics
• Online Access: https://hdl.handle.net/10356/148381
• Institution: Nanyang Technological University

In this study, numerical simulation methods were used to analyze the flow characteristics of annular impinging jets on surfaces of two different geometric models. The simulation results of the impinging jet on the surface of the flat-plate show that in the experiment where the jet separation distance H is 4Do, 2Do, and 1Do. Do is the inner diameter of the outer nozzle. The separation distance will greatly affect the the turbulent structure and shear stress distribution of the recirculation bubble, the wall impinging region, and the jets separated at the central stagnation point. For the impingement on round cylinder, the numerical simulation of the annular impinging jet with diameter ratios of d/Do = 1, 2, and 4 was carried out under the condition of separation distance H/Do=4. The final results show that on the flat surface with a larger separation distance, and on the convex surface with a smaller diameter ratio , the high intensity shear flow shear flow and turbulence make the impinging jet more capable of flow and spreading on the flat surface, which also means more effective heat transfer performance.