车用散热器中百叶窗翅片倾斜角度的研究

An Investigation of the Oblique Angle for Louvered Fins in Vehicle Radiators

本文采用萘升华质-热比拟技术,对车用散热器中百叶窗翅片的二维模型,即顺排倾斜板簇的换热与阻力特性进行了试验研究,并用氢泡可视化技术观察了倾斜板簇入口段的流动情况。试验中倾斜板簇共有6种倾斜角度,试验结果表明:当倾斜角度增大时,换热得到强化,同时阻力也将增加,但它们在不同的角度和流速时两者增加的比例不同。为此,作者推荐了一组以流速和倾角为参变数、换热系数α相对于压力梯度(-dp/dx)的“权衡”曲线的新方法。在设计不同用途的散热器时,这组曲线可以提供百叶窗翅片倾角的合理选择。

The heat transfer and pressure drop data for arrays of interrupted platespositioned obliquely to air flow direction are presented.Such an array ofplates can be served as a two dimensional model of louvered fins in vehicleradiators.Six different oblique angles of plate arrays were investigated.The heat transfer data were obtained via the naphthalene sublimationtechnique,and the flow pattern in the entrance region of oblique arraywere observed by the hydrogen bubbles visualization technique.Experimentalresults indicate that both the intensity of heat transfer and pressure drop areincreased with the increase of oblique angle.Consequently,an attempt ofso called trade-off method is made to compromize this contradiction.Thesetrade-off curves can provide a guidance for selecting the oblique angle.