Numerical Investigation of Inlet Velocity and Aspect Ratio Effects on Heat Transfer and Pressure Losses in Regenerative Cooling Channels

Abstract

This study investigates the effect of channel aspect ratio and inlet velocity on heat transfer and pressure losses in rectangular channels cooled by forced convection using methane as a coolant. The study employs a copper alloy channel with three configurations: Rec-1 (aspect ratio < 1), Rec-2 (aspect ratio = 1), and Rec-3 (aspect ratio > 1). Numerical simulations using ANSYS Fluent 18.1 revealed that increasing inlet velocity significantly enhances heat transfer, with a 118% difference in heated wall temperature  between 5 m/s and 15 m/s, but also causes a substantial rise in pressure losses (240%). Aspect ratio modifications demonstrate distinct advantages: Rec-1 minimizes external wall temperature , crucial for composite materials; Rec-2 achieves the lowest pressure losses; and Rec-3 reduces  without a significant increase in pressure losses. These findings provide valuable insights into optimizing regenerative cooling systems in rocket engines by balancing thermal performance and hydraulic losses.