6. Calculation of Drag Coefficient of a Sphere and Heat Transfer from It to a Gaseous Flow

The hypothesis about the influence of the early drag crisis of sphere on its heat exchange with gas was confirmed by mathematical modeling. First, the numerical simulation of the gas flow around the sphere in a cylindrical channel was carried out with the calculation of the drag coefficient of sphere and heat transfer from it to a gas. Second, the same was done for the case of flow around the sphere by a free gas stream, both laminar and strongly turbulent. In the latter case, it was found that the early crisis of drag for the sphere is accompanied by a crisis of its heat exchange with gas. In addition, the numerical simulation of the heat exchange of a drop of liquid with a gas stream was carried out without taking into account its evaporation.