Optimization of louvered-fin heat exchanger with variable louver angles. (5th December 2015)

• Record Type: Journal Article
• Authors: Jang, Jiin-Yuh; Chen, Chun-Chung
• Is Part Of: Applied thermal engineering. Volume 91(2015:Dec.)
• Page Start: 138
• Page End: 150
• Publication Date: 2015-12-05
• Subjects: Optimization -- Variable louver angle -- Conjugate gradient method -- Louvered-fin heat exchanger; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2015.08.009
• Languages: English
• ISSNs: 1359-4311

Abstract

Abstract: The optimization of the variable louver angle ( Δ θ ) and initial louver angle ( θ i ) for a louvered-fin heat exchanger was determined numerically using the conjugate gradient method. The area reduction ratio relative to a plain surface was the objective function to be maximized. A search for the optimal variable louver angle ( Δ θ ) and initial louver angle ( θ i ), in the ranges of +0° < Δ θ < +4° and 18° < θ i < 30°, respectively, was performed. The results show that the maximum area reduction ratios are 48.5%–55.2% for the optimal design of ( Δθ, θ i ) at ReH = 133–1199 ( U in = 1.0–9.0 m/s). In order to validate the reliability of the numerical simulation procedure, a comparison of experimental and numerical simulation results was made with the scaled-up testing. This article shows the temperature for the scaled-up louvered fin as determined from infrared thermovision and numerical simulation, respectively. A comparison of images shows that both methods give similar temperature distributions across the entire louvered fin. In addition, it shows comparisons of j and f between the simulation and experimental results. The results show good agreements, with a maximum discrepancy of 12%. Highlights: Optimization of variable and initial louver angle was performed. The maximum area reduction ratios may up to 44–51%. Numerical results were validated by Infrared thermovision data.