This paper proposes a technique based on a MAT-LAB code capable of getting an optimized preliminary design of an efficient low-speed compressor qualified for laboratory experiments with relatively low cost. The code was made to design five repeated compressor stages on two steps conducted iteratively, namely 'mean line and radial design' to determine the optimum compressor geometry and then the 'off-design' to test the stability of the design in other working conditions. The optimization tool minimizes a flexible cost function which can be changed if needed to get different designs. A certain

The number of words should not exceed 350. A three-dimensional numerical model for HVAC induced flow is presented. The nonlinear set of buoyancy driven incompressible flow equations, augmented with those of energy and k-ϵ turbulence model is solved. Various relevant are discussed. These challenges include avoiding expensive commercial packages, modelling complex boundaries, and capturing near wall gradients. Adaptive time stepping is employed to optimize computational effort. Threedimensional simulation requirements are addressed using parallel computations. Twodimensional and three

Route optimization is tactically important for companies that must fulfill the demands of different customers with fleet of vehicles, considering multiple factors like: The cost of the resources (vehicles) involved and the operating costs of the entire process. As a case study, a third-party logistics service provider, ABC Company, is introduced to implement optimization on. Furthermore, ABC Company's problem is defined as route optimization and load consolidation problems that will be solved as heterogeneous vehicle routing problem with soft time windows (HVRPSTW). In this paper's case

This study aims to investigate the Hitec molten salt's thermal-hydraulic behavior in a smooth round pipe under broad ranges of surface heat flux and Reynolds number (q = 104 - 105 W/m2, Re = 104 - 105). Mesh independent study was performed to ensure the robustness of the model to achieve accurate solutions. Presentation of temperature, pressure and thermophysical properties for multiple cases are presented and discussed. Temperature gradient decreases at high Reynolds number leading to small change in thermo-physical properties. While pressure seems not to be affected by the change in the

An analytical model for the filtration efficiency of face masks is developed. The model considers the effect of gap leakage due to the improper fitting of the face mask in the reduction of the effective filtration efficiency. The model is also extended to include the case with multiple face masks. The model results are verified using experimental data from literature. It is shown that the adverse effect of the gap leakage depends on the face mask filtration and leakage characteristics. It is also shown that wearing more than one face mask might not always be beneficial in some scenarios

The effect of the rate of change of fresh air inside passengers’ wagons for Underground Metro on the spreading of airborne diseases like COVID-19 is investigated numerically. The study investigates two extreme scenarios for the location of the source of infection within the wagon with four different air change rates for each. The first scenario considers the source of infection at the closest point to the ventilation system while the other places the infection source at the farthest point from the wagon ventilation system. The effect of the wagon windows’ status (i.e. closed or open) is also

In this contribution, a simple yet effective design for Schlieren photography system is described and implemented. The proposed system is used in the visualization of both heat and mass transfer phenomena. Refractive index gradient is created by a lighter to study mass transfer, then the lighter is ignited to create temperature gradient. Results show the ability of the proposed system in capturing the gradients in both mass and temperature gradients. © 2020 IEEE.

Water waves propagation over submerged obstacles is considered. The problem serves as an efficient model for modeling breakwaters. A numerical wave tank is developed to simulate the induced flow field. The model is based on multiphase viscous flow assumptions. Computations are performed adopting clustered grids and suitable initial and boundary conditions. The results are verified using the flow field particle image velocimetry (PIV) measurements. Spatial and temporal resolutions are validated. Complex flow phenomena occurring due to the presence of the relatively large sized obstacle are

In this paper, we introduce active material for an organic solar cell with a modified composition. A combination of P3HT: PCBM with parallel vertical LiF cylinders formulate the active material structure. The collection efficiency in the active material reaches 92.2%. The operating wavelength where the maximum collection efficiency occurs is adjusted and matched with the wavelength where the maximum irradiance of the solar spectrum occurs. The absorption per unit volume of the new structure is 80.4 μm-3 while the blank structure is 75.07 μm-3. The net absorption magnitude for the required

Background: The buckling load as well as the natural frequency under axial load for non-prismatic beam is a changeling problem. Determination of buckling load, natural frequency, and elastic deflection is very important in civil applications. The current paper used both perturbation method (PM), analytic method, and differential quadrature method (DQM), numerical method, to find buckling load and natural frequency with different end supports. The deflection of the beam resting on an elastic foundation under transverse distributed and axial loads is also obtained. Both PM and DQM are used for