Dissipation rate

Ds E Surface diffusivity Energy dissipation rate/mass m /s or cm /s ft /h... 

Energy dissipation rate per unit mass of fluid (ranges 570 < Ns < 1420) fluid and sphere, m/s. Cq,. = drag coefficient for single particle fixed in fluid at velocity i>,.. See 5-27-G for calculation details and other applica- ... 

E = Energy dissipation rate per unit mass of fluid... 

Turbulent velocity fluctuations ultimately dissipate their kinetic energy through viscous effects. MacroscopicaUy, this energy dissipation requires pressure drop, or velocity decrease. The ener dissipation rate per unit mass is usually denoted . For steady ffow in a pipe, the average energy dissipation rate per unit mass is given by... 

Turbulent kinetic energy dissipation rate density (m s ) = Turbulent viscosity (kg m sec )... 

Mersmann and Geisler, R., 1991. DeteiTnination of the local turbulent energy dissipation rates in stirred vessels and its significance for different mixing tasks. In 4th World Congress of Chemical Engineering. Karlsruhe, Germany. 

The concept of turbulent flame stretch was introduced by Karlovitz long ago in [15]. The turbulent Karlovitz number (Ka) can be defined as the ratio of a turbulent strain rate (s) to a characteristic reaction rate (to), which has been commonly used as a key nondimensional parameter to describe the flame propagation rates and flame quenching by turbulence. For turbulence s >/ />, where the dissipation rate e and u, L and v... 

Pitsch, H. and Steiner, H., Scalar mixing and dissipation rate in large-eddy simulations of non-premixed turbulent combustion, Proc. Combust. Inst., 28, 41, 2000. 

Volume rendering of scalar dissipation rate in a DNS of a temporally evolving CO/Hj jet flame. Re = 9200 [16]. The highest values of scalar dissipation rate (shown in red) exceed 30,000 S . ... 

An approximation of the flow field by a large eddy simulation (LES) formulation of the measured large eddies gives a reasonable estimation of the dissipation rate [7]. 

Short fixed beds are better than stirred reactors. Here a bed with a height of 10 cm arranged in a circulation loop for the control of pH was used. Although the average dissipation rate in the fixed bed with e = 7.2 and 64 mVs is much... 

Fig. 6. Estimates of fluid energy dissipation rates in different items of bioprocess equipment...

In all of the above equations, is assumed to be constant and uniform throughout the flow field. In most items of bioprocess equipment, however, there is a spatial distribution of energy dissipation. The definition of an average or a maximum energy dissipation rate is notoriously difficult in the case of bioprocess equipment such as high pressure homogenisers, centrifuges, pumps and microfiltration units which all have complex flow fields. 

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