abstract one of the most frequently encountered cases of rapid varied flow is the hydraulic jump. it occurs when a supercritical open channel flow changes into sub critical flow. in the present research, the experimental study of the hydraulic jump on seven sinusoidal corrugated beds with different wave steepness. the wave steepness of sinusoidal corrugated beds is in the range of 0.1667 to 0.7...

A unique in-house designed experimental apparatus for investigation of nucleation of droplets in CCS relevant systems is being developed by our team. The nucleation is measured with the help of a rapid pressure drop within an expansion chamber. In this study, a CO2 branch representing an important part of the mixture preparation device (MPD) was designed, assembled and tested. MPD is intended f...

The esterification reaction of phthalic anhydride with methanol was performed at different temperatures in a continuous flow glass microreactor at pressures up to 110 bar and using supercritical CO(2) as a co-solvent. The design is such that supercritical CO(2) can be generated inside the microreactor. Substantial rate enhancements were obtained, viz. a 53-fold increase was obtained at 110 bar ...

Steep topography on the ocean bottom, when underneath an oscillating tide, is not only associated with significant internal wave generation at the tidal frequency but also nonlinear flow features, large overturns and turbulent flow. Here, we investigate the internal wave dynamics and turbulence at an isolated steep obstacle using a three-dimensional, high-resolution large eddy simulation (LES)....

The paper presents the application of artificial neural network (ANN) to determine the end-depth-ratio (EDR) for a smooth inverted semicircular channel in all flow regimes (subcritical and supercritical). The experimental data were used to train and validate the network. In subcritical flow, the end depth is related to the critical depth, and the value of EDR is found to be 0.705 for a critical...

Enzyme efficiency was investigated in the lipase-catalyzed hydrolysis of canola oil in supercritical carbon dioxide (SCCO2). Immobilized lipase from Mucor miehie (Lipozyme IM) was used as the catalyst and the results showed that enzyme efficiency dropped at high pressures indicating a possible change in enzyme microstructure. Therefore, scanning electron microscopy (SEM) was used...

Stability of a two-layer Dean flow in a cylindrical annulus with respect to three-dimensional perturbations is studied by a global Galerkin method. It is shown that for large inner radius of the annulus ~i! the instability becomes three-dimensional if one of the fluid layers is thin, ~ii! its onset is not affected by possible small deformations of the interface, and ~iii! multiple three-dimensi...

The objective of the present work is to extract lovastatin with minimum impurity by using supercritical carbon dioxide (SC-CO2). A strain of Aspergillus terreus UV 1617 was used to produce lovastatin by solid-state fermentation (SSF) on wheat bran as a solid substrate. Extraction of lovastatin and its hydroxy acid form was initially carried out using organic solvents. Among the different screen...

Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1-10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance of the low chara...