Flow and heat transfer from multiple slot air jets impinging on circular cylinders

This study presents flow and heat transfer predictions of multiple slot air jets impinging on circular cylinders using CFD (computational fluid dynamics). The distribution of Nusselt numbers around the cylinders for different Reynolds numbers (23,000-100,000), distances between the jets, and openings between them was determined for two and three jets and compared to simulations of a single jet. The flow characteristics and the heat transfer distribution around the cylinders are found to be dependent on the distance and the opening between the jets. The interaction between two jets is found to be most advantageous. The heat transfer increases for higher Reynolds number in general; for two jets the heat transfer in the stagnation point is Nu(s) = 0.20Re(0.68). For three jets, the heat transfer distribution is different on the outer cylinders, as compared to the cylinder in the centre. (C) 2004 Elsevier Ltd. All rights reserved.