The static Ledinegg instability in horizontal microchannels under different flow conditions and fluids pertinent to electronics cooling was studied experimentally and numerically. Two fluids, water at sub-atmospheric pressures and refrigerant HFE-7100, were examined for a range of heat fluxes, mass fluxes, and channel hydraulic diameters. Numerical predictions from the developed pressure gradient model agree well with results from the flow boiling experiments. The model was used to quantify the susceptibility of the system to the Ledinegg instability. A parametric instability study was systematically conducted with varying system pressure, heat flux, inlet subcooling, and channel size with and without inlet restrictor. Increasing system pressure and channel diameter, reducing parallel channel number and channel length, and including an inlet restrictor can enhance the flow stability in microchannels.
International Journal on Heat and Mass Transfer, 52 (25-26), December, 2009, pp.5661-5674.