Pressure Drop Measurements in Rectangular Micro - Channel Using Gas Flow

Due to the need for practical cooling technologies which could dissipate high heat fluxes, an experimental study of pressure drop in micro-channel was performed. In this work, laminar flow friction factors were determined using gas (air) as flow medium. Pressure drop vs flow rate data were used to evaluate friction factors in two parallel microchannels, namely MCP1 and MCP2 (1.0 mm deep x 0.240 mm width and 0.9 mm deep x 0.2 mm width, respectively). Each channel of length 192 mm fabricated on a 304 Stainless Steel substrate by chemical milling Reynolds number was covered between 24 – 5398 for MCP1 and 26 – 6233 for MCP2. Transient pressure drops measured within the channel itself to exclude entrance and exit losses. Friction factor – Reynolds number analyses show that the friction constant are identical as normal channels for gas flow in the laminar region. Transition region lies in Re > 500 and transition set off at lower Re ~ 500 in comparison to normal channel. The discontinuity in f – Re data identified as transition. Further, it may be possible to identify transition (from laminar region) as the deviation of non-dimensional pressure drop (NDPD) values.