Turbulent flow structure

The major mechanism of a vapor cloud explosion, the feedback in the interaction of combustion, flow, and turbulence, can be readily found in this mathematical model. The combustion rate, which is primarily determined by the turbulence properties, is a source term in the conservation equation for the fuel-mass fraction. The attendant energy release results in a distribution of internal energy which is described by the equation for conservation of energy. This internal energy distribution is translated into a pressure field which drives the flow field through momentum equations. The flow field acts as source term in the turbulence model, which results in a turbulent-flow structure. Finally, the turbulence properties, together with the composition, determine the rate of combustion. This completes the circle, the feedback in the process of turbulent, premixed combustion in gas explosions. The set of equations has been solved with various numerical methods e.g., SIMPLE (Patankar 1980) SOLA-ICE (Cloutman et al. 1976). 

Turbulent flow structure energy spectrum function, scale up... 

Information entropy offers a good possibility of becoming a consistent viewpoint to treat phenomena that must be expressed by the probability terms. By using information entropy, it will become possible to define the evaluation indices for mixing and separation operations/equipment, to estimate turbulent flow structure in a chemical equipment, to establish scale-up rules based on the turbulent flow structure, to present a general particle size probability density distribution, and to define the amount of anxiety/expectation. 

In the following section, the turbulent flow structure is discussed based on ESD by using information entropy. 

The turbulent flow field can be considered to be a non-linear system, and the turbulent flow structure that consists of various size eddies is affected by the non-linear terms. The formula that expresses ESD is discussed based on the uncertainty regarding the wave number of the fluctuation that is selected when a fluctuation is selected from the turbulent flow field9-13. In order to define the ESD formula, the following conditions and assumptions are set ... 

The pipe has not been treated as a chemical equipment but only as a means for transportation. However, recently, line mixing and inline reaction have been considered, and the scale-up rule for pipes comes into question. Therefore, the relationship between the pipe diameter and turbulent flow structure in a circular pipe must be clarified. 

To clarify the relationship between the pipe diameter D and turbulent flow structure, in other words, the number of eddy groups m. 

Until now, we have focused on Newtonian fluids. However, there are many kinds of non-Newtonian fluids in chemical industries, and the turbulent flow structure of non-Newtonian fluids has remained unknown. It is very important to solve this problem. In this section, the power law fluid is considered to discuss the turbulent flow structure because the power law fluid is a representative non-Newtonian fluid and it is easy to treat it mathematically. 

Applying a two-layer turbulent flow model, in which the turbulent flow structures are modelled differently for the bulk and wall regions. 

Eckelmann, H., Nychas, S.G., Brodkey, R.S. and Wallace, J.M., Vorti-city and Turbulence Production in Pattern Recognized Turbulent Flow Structures, Phys. Fluids (1977), S225. 

The over-all structure in the undisturbed sandy clay before test likes turbulent flow structure, the... 

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