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The paper deals with a model of a liquid droplet vertically impinging on a heated solid surface. The model uses the following assumptions. The value of the wall temperature is taken to be such that the droplet-wall interaction would proceed via gas-vapor interlayer (T ≥ 400 °C). The droplet liquid is incompressible and nonviscous. The droplet surface is taken to be free, with its deformation caused by the effect of external pressure distributed over the droplet surface. The pressure is made up by two components, of which the first one is the surface tension pressure due to the curvature of the droplet surface; the second component is the pressure of vapor between the droplet and wall, which is determined by analyzing the process of vapor escape from the vapor interlayer. The motion of liquid within the droplet is taken to be potential and axisymmetric. The equations of droplet motion are solved relative to the potential of the vector field of velocity. The suggested model is used to perform numerical calculations of the droplet collision process, and the obtained results are compared with the data of other authors.

Computational results of 3D turbulent compressible gas flow in a single-nozzle ejector are compared with experimental data. Full Navier-Stokes equations and k-ε model of turbulence are used for mathematical model of gas flow. In computations the suction gas flow rate was determined and compared with experimental one. Two computational grids — coarse and fine are used to perform simulation. The fine grid is differ from coarse one by adaptation near the nozzle of active gas. Comparison of results carried out on coarse and fine grids shows that the accuracy of coarse grid is enough to get reliable results. Difference of computed and experimental results is less then 4% for the flow rate of passive gas. These results enable to make computational study of the multi-nozzle water-steam ejector. Condensation of steam is taken into account by introducing the equilibrium model of condensation. It is found that location of nozzles and its length are the important parameters of ejector influencing considerably its characteristics. The process of the condensation of water vapor significantly influences the work of ejector with an increase of the suction flow rate by a factor of 2.

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