Turbulent single-phase flow

When the flow is highly turbulent single phase, there are many design options, including  

Special features of these design options are described below. 

2 Valves, Nozzles, and Orifice Plates. These devices provide some degree of control of the mixing process versus empty pipe. Mixing length can be 

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The problems of micro-hydrodynamics were considered in different contexts (1) drag in micro-channels with a hydraulic diameter from 10 m to 10 m at laminar, transient and turbulent single-phase flows, (2) heat transfer in liquid and gas flows in small channels, and (3) two-phase flow in adiabatic and heated microchannels. The smdies performed in these directions encompass a vast class of problems related to flow of incompressible and compressible fluids in regular and irregular micro-channels under adiabatic conditions, heat transfer, as well as phase change. 

D. The Simulation of Processes in a Turbulent Single-Phase Flow... 

The "correlative" multi-scale CFD, here, refers to CFD with meso-scale models derived from DNS, which is the way that we normally follow when modeling turbulent single-phase flows. That is, to start from the Navier-Stokes equations and perform DNS to provide the closure relations of eddy viscosity for LES, and thereon, to obtain the larger scale stress for RANS simulations (Pope, 2000). There are a lot of reports about this correlative multi-scale CFD for single-phase turbulent flows. Normally, clear scale separation should first be distinguished for the correlative approach, since the finer scale simulation need clear specification of its boundary. In this regard, the correlative multi-scale CFD may be viewed as a "multilevel" approach, in the sense that each span of modeled scales is at comparatively independent level and the finer level output is interlinked with the coarser level input in succession. 

The validation of mesoscale models can be carried out using the numerical solutions to microscale models (Tenneti et al, 2010), in much the same way as that in which DNS is used for model validation in turbulent single-phase flows. A typical mesoscale modeling strategy consists of four steps. 

Higher heat transfer rates in turbulent microchannels than predicted by traditional large-scale correlations were observed by Adams et al. [23]. Based on the work of Gnielinski, a generalized correlation for turbulent single-phase flow in microchannels is derived ... 

Jenne and Reuss [44] performed critical assessments of the use of k-e turbulence models for simulations of turbulent single phase flow induced by the impellers in... 

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