Effect of sand particles on flow structure of free jet from a nozzle

Abstract

The Characteristics of single and two- phase flow from a circular turbulent free jet from a nozzle of 10 mm diameter were investigated experimentally and numerically. The measurements were conducted for ReJ = 10007 - 31561. The velocity was measured at location from the nozzle y/D (0-8) in axial and radial directions. The two phase measurement were done by using natural construction sand as a solid phase of sizes (220,350,550) µm and loading ratios (mass flow ratio of sand to mass flow rate of air) in the range (0.18-1.38). Two phase air velocity of jet showed that the introducing of natural sand particles gives lower jet velocity attributed to momentum transfer to particles. The smaller particle size leads to lower values of velocity. The velocity found to be decreased with loading ratio increase. The numerical simulation was performed for single and two phase jet flow. RNG K-ε turbulence model was used to simulate the flow of fluid and the discrete phase model to simulate the particles flow. The results form numerical simulation showed a good agreement with experimental results.

Modeling of blood clot removal with aspiration Thrombectomy devices

“…However, it is observed that the gelatin twisted (see ink lines in figure) due to the torsional effect associated with the existing helix, which is reflected in the FEM simulation modeling results. The results obtained are consistent with previous Bond Graph models that indicated that the forces needed to extract a blood clot from an artery in in-vitro experiments are within the range ~40-90 kPa [21,22]. This indicates that the GPTAD may therefore have potential use in the removal of blood clots in human arteries because it will not potentially damage the arteries due to the suction operating pressure.…”

“…For this reason, experiments related to material properties [18], simulation methodologies [19] and nozzle effects [20] have been undertaken. Also, mathematical models have been developed in preliminary studies [21,22] to obtain the appropriate range of different parameters without the need for complex in-vitro or in-vivo experiments. In these studies, the clot removal is modelled with Bond-Graph method, paying attention to the whole system involved in the thrombectomy: pump, catheter, vessel, suction device, blood clot and the existing interfaces.…”