The effects of process parameters on the extraction of Ginkgo biloba L. leaves with supercritical carbon dioxide were investigated. The investigated parameters include particle size (mean particle diameter 0.19, 0.467 and 1.009 mm), solvent flow rate (1.58×10, 3.22×10 and 4.16×10 kg CO2/min) and pressure (100–300 bar), which were obtained by the response surface methodology (RSM) under the foll...

This paper presents transonic buffet simulations over a swept wing of supercritical airfoils with Unsteady Reynolds-Averaged Navier-Stokes (URANS) and Detached-Eddy Simulation (DES) methods. The NASA SC(2)-0714 airfoil is used as wing profile. Computations are conducted at free-stream Mach numbers from 0.72 to 0.84 for Reynolds number 45.0 × 10 based on aerodynamic chord length. Firstly, 2D NAS...

Studies of flow behind a single cylinder have greatly contributed to our understanding of the development of complex flows like the Kármán vortex street[1] or turbulent flows. At the first instability in such a system the laminar flow (LF) becomes time dependent and vortices appear. It has been shown that this transition to the vortex shedding phase (VS) is well described by the supercritical H...

In the present study, Radix Codonopsis was extracted by supercritical CO2 extraction. As Ointment collecting rate and the yield of stigmasterol are index, Various reaction parameters were changed to attain the optimal conditions. The appropriate process conditions are size 40 60Mesh, 30 Mpa pressure, temperature 65 °C, 120 min, entrainer Alcohol dynamic extraction (entrainer pump flow rate of 1...

Direct and large eddy simulations are performed to study the internal waves generated by the oscillation of a barotropic tide over a model ridge of triangular shape. The objective is to go beyond linear theory and assess the role of nonlinear interactions including turbulence in situations with low tidal excursion number. The criticality parameter, defined as the ratio of the topographic slope ...

We present a simple viscous theory of free-surface flows in boundary layers, which can accommodate regions of separated flow. In particular this yields the structure of stationary hydraulic jumps, both in their circular and linear versions, as well as structures moving with a constant speed. Finally we show how the fundamental hydraulic concepts of subcritical and supercritical flow, originatin...

Radial inflow turbines are the preferred architecture for energy extraction from the organic Rankine cycle and the supercritical CO2 Brayton cycle at smaller scales. For such turbines it is possible for fluid to be delivered to the first stage by either a volute or plenum delivery system. For high pressure supercritical CO2 turbines, there are no fully documented fluid delivery systems in liter...

With high pressures, supercritical fluids can be studied over a very wide range of density. Fluids with strongly interacting polar molecules for example water are of particular interest. Results for several thermophysical properties are discussed. Density, dielectric constant and self—ionization of water have been determined or predicted to 1000 °C. Beyond 20 GPa very hot water appears to becom...

In the present paper, thermal transport and entropy production mechanisms in a turbulent round jet of compressed nitrogen at supercritical thermodynamic conditions are investigated using a direct numerical simulation. First, thermal transport and its contribution to the mixture formation along with the anisotropy of heat fluxes and temperature scales are examined. Secondly, the entropy producti...

We consider radial solutions of a mass supercritical monic NLS and we prove the existence of a set, which looks like a hypersurface, in the space of finite energy functions, invariant for the flow and formed by solutions which converge to ground states. §