Microvalves can play an essential role in transport and control of fluids for biomedical applications. These valves may face reliability issues as they can fail due to deterioration of the moving parts exposed to prolonged and repeated movements or handling fluids that contain particles of several microns in diameter. An alternative to valves with moving parts are microdiodes such as micro vortex diode, which offers high resistance to flow in one direction and much smaller resistance in the opposite direction. The present study is focused on developing a two-step computationally-based approach for design and optimization of micro vortex diodes. A numerical design optimization based on the Design of Experiment and Response Surface Method is employed to improve the efficiency of a micro vortex diode using geometrical parameters. The results of the optimization study suggest an optimal design with about 69% improvement in efficiency compared to the reference design.

An approach for the optimization of laminar flow in diffusers is presented. The goal in our optimization process is to maximize diffuser performance and, in this way, pressure recovery by optimizing the geometry.Our methodology is the optimization through wall contouring of a given two-dimensional diffuser length ratio. The developed algorithm uses the CFD software: Fluent for the hydrodynamic analysis and employs surrogate modeling and an expected improvement approach to optimization. The non-uniform rational basic splines (NURBS) are used to represent the shape of diffuser wall with three to nine design variables, respectively. The framework is assisted by the construction of Kriging model, for the management of the problem. The CFD software and the Kriging model have been combined for a fully automated operation using some special control commands on the MATLAB platform. In order to seek a balance between local and global search, an adaptive sample criterion is employed. The optimal design exhibits a reasonable performance improvement compared with the reference design.

Channel flow with baffles is a multifaceted phenomenon with wide-ranging applications. It plays a crucial role in enhancing mixing, heat transfer, and other fluid dynamics processes. The baffles' design and placement within the channel are crucial to achieving the desired heat transfer enhancement. Based on the specific application and fluid properties, such as baffle geometry, spacing, and orientation must be considered. This work aims to visualize, evaluate, and understand the effectiveness of baffles on heat transfer rates under various operating conditions and design parameters.  Computational Fluid Dynamic (CFD) investigations were carried out to examine the performance of channels for various geometrical configurations including Broken V-shaped, Circular, and triangular at wide operating conditions, and baffle number densities. Computational fluid dynamic (CFD) simulations were carried out for three different baffle shapes while the Reynolds number (Re) ranged from 1800 to 22000 and the no. of baffle sets(N), varied as N=15,20,30. At low Re conditions channel with 30 sets of Broken-V-shape baffles results in a higher Nusselt number due to effective turbulence enhancement and mixing in the channel. Although the thermal performance of a V-shaped baffles case is relatively good the friction factor is more for this case. Triangular baffles exhibited a lower friction factor. A maximum friction factor of 0.92 is observed for N=30 sets at Re= 1800 while the least of 0.76 is recorded for N=15.

This paper investigates the improvement of the bow region of the trimaran ship hull, and proposes a Computational Fluid Dynamics (CFD)-based automated method to reduce total resistance. The main objectives pursued in the present study include: 1) to create and develop a useful optimization platform to modify the ship hull and 2) to investigate the e ect of di erent inverted bow on the hydrodynamic performance of trimaran ship. A wave-piercing bow trimaran hull was taken as the baseline design. The ship bow has been redesigned using Arbitrary Shape Deformation (ASD) technique, which de nes the input variables for the optimization process. The objective function was the drag force, and this study is conducted at cruise speed. To accomplish this task, two optimization methods were sequentially applied. A Latin Hypercube Sampling tool distributes design points and an Radial Basis Function (RBF)-based surrogate model is constructed to investigate system behavior. The  nal optimum design of Design Of Experiment (DOE) study was introduced to the direct optimization SHERPA algorithm as a baseline design. The integration of CFD solver, geometric parameterization and optimizer tools is managed by the HEEDS MDO software package using a multi-connection method. The optimization results show that the optimization was successfully carried out and the resistance was reduced by 10. 2%. The comparison between the initial hull and the optimized hull shows that the proposed optimization platform can be used for ship hull optimization in industrial application and signi cantly reduces the computational time and workload.

In the present study, a Gorlov Vertical Axis Wind Turbine (VAWT) in small dimensions was numerically simulated using the Computational Fluid Dynamics (CFD) method. The purpose of this study is to investigate the effect of design and operational parameters on the Gorlov VAWT performance. In order to evaluate the efficiency of this turbine, two parameters of power and torque coefficients are calculated, and their values ​​are compared in the different Tip Speed Ratios (TSR). This paper investigates effective parameters namely inlet wind velocity, blade chord length, helical angle, aspect ratio, and blade airfoil profile. The results show that the turbine with V=15(m/s), c =0.25(m), ψ =30(deg), φ= 2.3 increased maximum Cp by 75%, 273%, 30% and 250%, respectively. In order to find optimal conditions to achieve a higher value of Cp, the Kriging optimization method is provided. The results of Cp show that the highest efficiency of Gorlov VAWT is related to an inlet wind velocity of 15 (m/s), an aspect ratio of 2.3, a helical angle of 30 degrees, a chord length of 0.25 (m), and NACA0018 airfoil profile at TSR of 1.8. Also, sensitivity analysis indicates that blade chord length and helical angle have more effect on mentioned VAWT performance. The Cp and Cm in the mentioned conditions are high enough thus it helps self-starting capability.