Author(s): V. P. Rogounovich; F. D. Shnipov
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Keywords: No Keywords
Abstract: The paper deals with a calculation method for transverse averaged velocity compo- nents in longitudinally uniform re ctangular and trape zoidal duc ts with nan-uniforme pe ri phe ral roughness. Using the Reynolds initial e quations, the autors have obtained a system of two partial differential e quations of the 4th and 2th orders to be used for the stu- dy of thre e-dimensionel field of averaged velocities. Turbulent stresses are determined with the aid of 1st order turbulent model, wich satisfactorily simulates anisotropy of the cross-se ctional distribution of the normal components. The system of e quations of motion is completed to a first approximation by semi -empirical relation for the longitu- dinal velocity, which pre dicts with a 3% error at a confidence level of 0.95. The cross se- ctional distribution of the net kinematic viscosity is obtained for solution of the Cauchy problem for the pertial differential equetion of the 1st order. After introduction of the velocity vortex, the fourth-order e quation for the stream function of transve rse circulation is substituted by a system of two separate partiel differential e quations of the 2nd order, for which the Diri chlet problems to be solved numerically are f ormulated. The predicted net kinematic viscosities, turbulent stresses and treansverse components of the average velocity agree as a rule with the experimental date within the confidence range of 0.95.
Year: 1985