## Abstract

In the present study, successively increased or decreased louver angle patterns are proposed and 3-D numerical analysis on heat and fluid flow are carried out. Five different cases of successively increased or decreased louver angles (+2°, +4°, -2°, -4°, and uniform angle 20°) are investigated: case A (20°, 22°, 24°, 26°, 24°, 22°, 20°), case B (20°, 24°, 28°, 32°, 28°, 24°, 20°), case C (26°, 24°, 22°, 20°, 22°, 24°, 26°), case D (32°, 28°, 24°, 20°, 24°, 28°, 32°), case E (uniform angle 20°) . For case A (+2°), case B (+4°), case C (-2°) and D (-4°), the maximum heat transfer improvement interpreted by j/j_{0} are 115%, 118%, 109% and 107%, and the corresponding friction factor ratio f/f_{0} are 116%, 119% 110% and 108%, respectively, where j/j_{0} and f/f_{0} are the Colburn factor ratio and friction factor ratio between successively variable louver angles and uniform angle, respectively. It is also shown that the maximum area reduction for case B can reach up to 25.5% compared to a plain fin surface. The present results indicated the successively variable louver angle patterns applied in heat exchangers could effectively enhance the heat transfer performance.

Original language | English |
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Pages (from-to) | 1629-1639 |

Number of pages | 11 |

Journal | Applied Thermal Engineering |

Volume | 26 |

Issue number | 14-15 |

DOIs | |

Publication status | Published - 2006 Oct 1 |

## All Science Journal Classification (ASJC) codes

- Energy Engineering and Power Technology
- Industrial and Manufacturing Engineering