Experimental study of pressure drop oscillations in parallel horizontal channels

Two-phase flow instabilities are an undesirable phenomenon present in many fields and scales, ranging from large heat exchangers and boilers in industrial applications to micro-scale heat exchangers for high density power electronics. In the present study pressure drop oscillations in a two parallel horizontal channels system have been experimentally investigated, focusing in the individual behavior of each channel. The balanced (same characteristic pressure drop curve) and unbalanced cases have been analyzed finding different limit cycles than the typical single channel case. No pressure drop oscillations with both channels following the typical limit cycle were found. The oscillation mode detected consisted in one channel performing the usual limit cycle, while the other was always oscillating in the superheated vapor region.