Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Chemical and Process Engineering

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: fluctuation velocity

Sortuj według:

Ogranicz wyniki do:

Local Turbulent Energy Dissipation Rate in a Vessel Agitated by a Rushton Turbine

Šulc R., Pešava V., Ditl P.

Chemical and Process Engineering

2015

Vol. 36, nr 2

135--149

The scaling of turbulence characteristics such as turbulent fluctuation velocity, turbulent kinetic energy and turbulent energy dissipation rate was investigated in a mechanically agitated vessel 300 mm in inner diameter stirred by a Rushton turbine at high Reynolds numbers in the range 50 000 < Re < 100 000. The hydrodynamics and flow field was measured using 2-D TR PIV. The convective velocity formulas proposed by Antonia et al. (1980) and Van Doorn (1981) were tested. The turbulent energy dissipation rate estimated independently in both radial and axial directions using the one-dimensional approach was not found to be the same in each direction. Using the proposed correction, the values in both directions were found to be close to each other. The relation /(N3·D2)  const. was not conclusively confirmed.

Study of the turbulent flow structure around a standard Rushton impeller

Kysela B., Konfršt J., Fořt I., Kotek M., Chára Z.

Chemical and Process Engineering

2014

Vol. 35, nr 1

137--147

The velocity field around the standard Rushton turbine was investigated by the Laser Doppler Anemometry (LDA) and Particle Image Velocime try (PIV) measurements. The mean ensemble-averaged velocity profiles and root mean square values of fluctuations were evaluated at two different regions. The first one was in the discharge stream in the radial direction from the impeller where the radial flow is dominant and it is commonly modelled as a swirling turbulent jet. The validity range of the turbulent jet model was studied. The second evaluated region is under the impeller where flow seems to be at first sight rather rigorous but obtained results show nonnegligible values of fluctuation velocity.