Numerical Investigation on Heat Transfer and Fluid Flow Behaviors of Viscous Fluids through Minichannel Heat Exchanger.

摘要

Miniature heat exchanger concept is gaining popularity in automotive and other industrial applications due to enhanced heat flux, light weight, and larger heat transfer area density compared to conventional heat exchangers. Heat transfer and flow characteristics of different viscous liquids, such as engine oil, automatic transmission fluid, 50% ethylene glycol, and Deionized water were numerically analyzed through a multi-port serpentine minichannel heat exchanger (MICHX). Hot liquids of different flow rates at constant temperature of 76°C were cooled by a constant air temperature of 14°C and flow rate of 507g/s. The heat transfer performance of engine oil was found poor compared to other fluids. Pressure drop in MICHX for engine oil was also found extremely higher compared to water. However, the distribution of temperature, mass flow rate, and heat transfer rate in each channel is more even for high-viscosity fluids compared to low-viscosity fluids. The entrance region effects in thermal and flow fields for high-viscosity fluids were observed negligible.