关于地球椭圆体面上等角航线解算的实用公式

为了克服计算航法在地球圆球体上解算精度低的缺点,研究了地球椭圆体面上进行等角航线(恒向线)正、反解算的理论,并以算例进行校核。等角航线的解算实用公式适用于近、中程航海。比如当船舶在海上按某一等角航线航行时,有时采用计算航法。即根据船舶的航向K、航程S和船舶出发点的地理坐标(1,λ1),用计算航法求得到达点的地理坐标(2、λ2)。沿用大地测量学的习惯,我们称它为等角航线问题的正解;反之,若已知等角航线上某两点的地理坐标,需要求知等角航线的航向和航程时,我们称之为等角航线问题的反解。     

Design of conformal cooling channels for an automotive part

The cooling system plays a crucial role in determining the productivity and quality of an injection molding process. With the current growth of Solid Freeform Fabrication (SFF) techniques, mold designers have been striving for not only improvement in cooling system performance but also for a method to do so automatically. In this paper, a method is proposed for developing a conformal cooling system that facilitates uniform cooling over the entire mold surface with minimum cycle time. Based on the temperature distribution after the filling stage, the mold surface is split into zones which will be cooled by optimized subconformal channels obtained from the optimization process. The optimization process in which the objective function is stated as minimization of the cooling time with boundaries ensuring a realistic design will optimize the cooling system layout in terms of cooling channel size and location. Finally, all subcooling channels are combined to generate the entire conformal cooling system for the injection mold.