Vibration Analysis of Cylindrical with Splitter Plates under Different Deflection Angles at High Reynolds Number

In order to study the influence of the splitter plate in the elastic support system, the SST k-omega turbulence model is used to solve the problem, and the cylindrical system with splitter plate is numerically simulated by overset mesh. This paper studies the effect of the splitter plate on the vibration system at different deflection angles. The results show that the splitter plate has little effect on the system when the deflection angle is low. When the deflection angle is about 10 degrees, the system vibration characteristics will have a sudden change, the amplitude will decrease, and the vortex frequency will increase. Between the deflection angle of 10 degrees and 45 degrees, as the deflection angle increases, the amplitude increases and the vortex frequency decreases. It can be seen from the motion trajectory that the deflection angle changes suddenly after 10 degrees, and the system has a very small amplitude between 10 degrees and 25 degrees. In this declination interval, the splitter plate controls the vibration of the cylindrical system better.

Fluid flow and heat transfer around square cylinder with dual splitter plates arranged at novel positions

In this paper, the effect of the dual splitter plates on the fluid flow and heat transfer characteristics around a regular square cylinder for a low Reynolds number flow ( Re = 100) is presented. The placement of the dual splitter plates is novel of its kind as these plates are located at the top and bottom surfaces of the cylinder rather than the conventional locations, that is, at the upstream and downstream of the cylinder. Here, two splitter plates of the same width ( w) with varying lengths and location are considered. A numerical investigation is performed using the open-source code, OpenFOAM. A base solver, icoFOAM is used after modifying the code by incorporating the energy equation in it. The primary wake bubble is found closer to the cylinder rear surface when the dual plates are introduced. It is also noticed that the separation angle and the recirculation length are smaller in the dual plates cases than that are in the cases without the dual plates. A mixed effect of the dual plates on the fluid forces is observed in the present study. A maximum reduction on the mean drag coefficient and root mean square of the lift coefficient is found as 3% and 24%, and maximum increment as 75% and 87%, respectively. However, a substantial enhancement on the overall heat transfer is noticed with the dual plates compared to that of the bare cylinder. A maximum enhancement of 40% is observed in the heat transfer around the square cylinder. In addition, thermal-hydraulic performance is calculated for finding the trade-off between the fluid forces and the heat transfer. The maximum value of thermal-hydraulic performance is found as 1.35 in the present study depending on the mean drag coefficient and 3.65 depending on the root mean square of the lift coefficient. Further, a novel combined thermo-fluid regime is defined for the square cylinder with dual splitter plates from which the location of the plates can be determined according to the demand on the heat transfer and fluid forces.

Numerical optimization of microfluidic vortex shedding for genome editing T cells with Cas9

Microfluidic vortex shedding (µVS) can rapidly deliver mRNA to T cells with high yield and minimal perturbation of the cell state. The mechanistic underpinning of µVS intracellular delivery remains undefined and µVS-Cas9 genome editing requires further studies. Herein, we evaluated a series of µVS devices containing splitter plates to attenuate vortex shedding and understand the contribution of computed force and frequency on efficiency and viability. We then selected a µVS design to knockout the expression of the endogenous T cell receptor in primary human T cells via delivery of Cas9 ribonucleoprotein (RNP) with and without brief exposure to an electric field (eµVS). µVS alone resulted in an equivalent yield of genome-edited T cells relative to electroporation with improved cell quality. A 1.8-fold increase in editing efficiency was demonstrated with eµVS with negligible impact on cell viability. Herein, we demonstrate efficient processing of 5 × 106 cells suspend in 100 µl of cGMP OptiMEM in under 5 s, with the capacity of a single device to process between 106 to 108 in 1 to 30 s. Cumulatively, these results demonstrate the rapid and robust utility of µVS and eµVS for genome editing human primary T cells with Cas9 RNPs.