The flow of a viscous incompressible fluid in small gaps hydraulic devices and devices based on the hop boundary changes in viscosity. For the distribution model adopted dynamic viscosity was integrate the equations of fluid motion, whereby expressions are obtained for the velocity of the liquid height of the gap. The expressions for calculation of the fall capacity flow section are determined. Examples of the calculation of distributions velocity and falling bandwidth to a narrow gap are given.The estimation of the limits of applicability of classical approach to the calculation of viscous flow in micro gap is executed.
Acoustic radiation sources are successfully applied to cleaning rooms from dust of fairly large particle sizes (ten micrometers and larger). The sedimentation of fine aerosols (particle diameter of 1-10 microns) is a more complicated challenge. The paper is devoted to the substantiation of the acoustic sedimentation method for such aerosols. On the basis of the mathematical model analysis for aerosol sedimentation by the acoustic field the mechanisms of this process have been determined and include the particle coagulation acceleration and radiation pressure effect. The experimental results of the acoustic sedimentation of a model aerosol (NaCl) are shown. The calculation results according to the mathematical model for coagulation and sedimentation, on the basis of the Smolukhovsky’s equation taking into account various mechanisms of aerosol sedimentation by sound depending on the particle sizes and sound intensity, are given. The necessity to use intensive sources of high-frequency sound has been confirmed, suggesting that these sources must be located above dust clouds.
An alternative FEM algorithm of fi nding piston ring pressure distribution to a contact simulation is introduced. The method is basing on an analytical determining of required nodal displacement boundary conditions. Its several confi gurations are tested using APDL and compared to a no-separation contact simulation of a simple 2D fi nite element model of a two-stroke piston ring made of Titanium alloy. Each of the methods tested in the paper brings displacement result and Huber-Misses equivalent stresses close to each other. However, only one of those brings resulting contact pressure close to a no-separation contact simulation. Nonetheless, the obtained confi guration occurred to be less computationally effi cient than no- separation contact simulation performed in an ANSYS software.