Numerical Study on the Non-Uniformity of Secondary Flow Distribution in Minichannels

Efficient cooling is important for the normal operation of electronic devices. Minichannel heat exchangers are one of effective cooling devices for achieving higher power and more compact layout. The uniform flow distribution of coolant in each microchannel is a prerequisite for effective cooling in minichannel cooling systems. This paper studied the flow distribution of multiple parallel minichannels heat sinks through numerical simulation, and explored the flow uniformity under different inlet and outlet layouts and inlet mass flow rates. The calculated model included 9 heat dissipation plates, each containing 10 minichannels. The results indicate that during the primary flow distribution process to each heat sink, the flow uniformity is better when the inlet and outlet layout is in the “C” shape; In the secondary flow distribution process, the microchannel near the inlet and outlet of the heat sink has the highest flow rate, and the deviations of flow rate in each channel could reach 5–6 times the average value under ideal conditions. There is a backflow phenomenon in the channels on the left and right sides of the minichannel with the highest flow rate, and special attention should be paid in the cooling system design of electronic devices.