Numerical Study on Flow and Heat Transfer Characteristics in Dimpled Cooling Channel with Wedge-shape Vortex Generator

다국어 초록 (Multilingual Abstract)

This study numerically investigates the detailed flow structure and heat transfer characteristics of a newly designed dimpled cooling channel. The proposed surface geometry is a general dimple structure combined with a wedge-shaped vortex generator on the upstream dimple. The main purpose of the surface geometry is to enhance the flow mixing and heat transfer in the flow-recirculating region that is generated by the dimpled cooling channel. Direct numerical simulations were carried out with a Reynolds number of 2800 and Prandtl number of 0.71 in the cooling channel. The main design parameter is the width ratio between the cooling channel and vortex generator (W*). When W* increases, the heat transfer on the surface is enhanced because of the main counter-rotating vortex downstream of the computational domain. In the case of W*=0.4411, the volume goodness factor increases to approximately 30% compared to the general dimpled cooling channel.

목차 (Table of Contents)

• 1. Introduction 1
• 2. Numerical methodology 6
• 2.1. Governing equations 6
• 2.2. Configuration of novel surface shape 8
• 2.3. Computational domain and grid resolution 9
• 2.4. Calculation of the thermo-aerodynamics performance 10
• 3. Results and discussion 13
• 3.1. Flow characteristics 13
• 3.2. Time-averaged flow structure 14
• 3.3. Plain views of the mean flow and thermal fields 15
• 3.4. Pressure coefficient and Nusselt number 17
• 3.5. Thermo-aerodynamic performances 19
• 4. Conclusion 23