不可压缩流体横掠椭圆截面管道时的对流换热

Convective heat transfer in uncompressible fluid sweeping across ellipse cross section pipes

为获得不可压缩流体横掠椭圆截面管道时对流换热规律的一般性的认识,采用解析法与数值法相结合的方法,首先研讨了不可压缩粘性流体平面无环量椭圆绕流(动力)层流边界层的一些特征并将其应用于椭圆管面的对流换热问题,得到较为精密的椭圆管面局部对流换热系数的一般表达式,从而为在一个较广泛的视角下分析椭圆管的换热提供了一条途径。按此方法,对某一势流速度下局部换热系数与管形的关系给出了分析计算实例,并得到在此势流速度下,具有最大换热能力的椭圆管形。另外,基于笔者用函数论方法所得到的一个一般关系式,给出了一般椭圆管对流换热能力的一种估值。该方法和结果是对现有纯试验和纯数值方法的一个补充。

For a general understanding of the regularity of convective heat transfer in uncompressible fluid sweeping across the ellipse cross section pipes,some characteristics were analyzed concerning the ellipse flow laminar boundary by combining analytical methods with numerical methods.With those characteristics applied to the convective heat transfer problems on surface of ellipse pipe,a preciser formula was obtained for the local heat transfer coefficient of ellipse pipe.Thus,an approach,which can be used to analyze the heat transfer of ellipse pipe at an extensive viewpoint,was provided.These methods can help analyze the relationship between the local heat transfer coefficient and the pipe shape so as to obtain the ellipse pipe shape with extreme heat transfer capacity.Moreover,using a general formula obtained according to the theory of functions led to a general estimation on capacity of convective heat transfer of ellipse pipes.The methods and results obtained are a supplement to the pure experimental and pure numerical methods.