Lateral-flow effect on pressure drop and lateral mass flow rate distribution in pin-fin trapezoidal duct

Experiments were conducted to determine the distributions of static pressure and lateral mass flow rate in a pin-fin trapezoidal duct that models the cooling passages in gas turbine blades. The ratio of lateral-to-total flow rate c was varied from 0.3 to 1. The flow Reynolds numbers were varied from 5 × 10⁴ to 9 × 10⁴. The results show that: The pressure drop along chordwise is much larger than that along radial. The lateral flow rates near the root and the top of the blade are larger than that in the middle region. The lateral mass flow rate distribution is dependent on the lateral-to-total mass flow ratio. The difference between the segmental lateral flow rates increases as the lateral-to-total mass flow ratio decreases from 1 to 0.3. The results also show that the total pressure drop coefficient decreases with increasing lateral-to-total flow rate.