Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: kinetic energy losses

Sortuj według:

Ogranicz wyniki do:

Energy losses in big band saw machines – analysis and optimization

Marinov Boycho

Archive of Mechanical Engineering

2020

LXVII, nr 3

335--351

In this paper, the energy losses in big band saw machines are investigated. These losses are caused by the geometric and angular inaccuracies with which the leading wheels are made. Expressions for calculating the kinetic energy of the mechanical system in the ideal and the real cases are obtained. For this purpose, expressions for calculating the velocities of the centers of the masses in two mutually perpendicular planes are obtained. A dependence for calculation of the kinetic energy losses of the mechanical system in final form is received. Optimization procedure is used to determine the values of the parameters at which these losses have minimum values. The proposed study can be used to minimize energy losses in other classes of woodworking machines.

On the prediction of flow patterns and losses in HP axial turbine stages using 3D RANS solver with two turbulence models

Lampart P., Świrdyczuk J., Gardzielewicz A.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

2001

Vol. 5, No 2

191-206

An experimentally tested air turbine stage and a real high-pressure (HP) steam turbine stage are calculated using the 3D RANS solver FlowER supplemented with the Baldwin-Lomax and Menter shear stress transport (SST) models. The computations of the model air turbine stage show that the Menter SST model gives better agreement with the experimental data as far as the span-wise distribution of exit velocities and swirl angle. The comparison of performance of the two turbulence models exhibits differences in predicting flow patterns and losses in the considered HP turbine stage. The main differences concern the development of secondary flows and separations. There is a significant span-wise redistribution of losses between these two models. The tendency is that for the same relatively refined grid resolutions, the level of pitch/span averaged losses for the Menter SST turbulence model is slightly above that of Baldwin-Lomax.