Experiments of Ethylene Glycol-water Mixture in Multi-port Circular Straight Microchannel Slab

Microchannels (diameter of 1 mm or less) have received significant research attention nowadays due to their high heat transfer and space saving capability compared to the conventional sized tubes for a given heat duty. Use of microchannel core can make an automotive heat exchanger further light-weighted and down-sized while keeping the heat duty similar or even higher as compared to the traditional compact heat exchangers. Automotive engine generally uses heat exchange process in air-glycol crossflow orientation for its cooling system. Research and thermo-hydrodynamic design correlations and sufficient experimental data on single-phase pressure drop and heat transfer using multi-port microchannel slab in air-to-glycol crossflow orientation is rare in the open literature. The availability of a well instrumented dynamic test facility, i.e. both fluids are in motion, for such research is also limited.

In ongoing long-term research, a well equipped dynamic real-life single-phase air-to-liquid crossflow fluid flow and heat transfer experimental facility has been developed and commissioned. The test bench and its instrumentation could handle the experiments of water; ethylene glycol; and engine, transmission, and other oils in a variety of microchannel geometry and operating conditions. In the ongoing series, experiments have been conducted to obtain the general data on the hydrodynamic characteristics of 50% ethylene glycol-water mixture in multi-port straight microchannel test slab. The paper presents the pressure drop behavior of ethylene glycol-water mixture and the Reynolds number effects on the pressure drop, friction factor and Poiseuille number in the classical laminar flow regime.