Maysam Saidi

Razi University | razi · Department of Mechanical Engineering

The motion effect on the contaminant dispersion is a key parameter in cleanrooms. This parameter is ignored in many experimental and numerical studies because of its complexities, but could cause errors in the obtained results. In real situations, particularly in the isolating rooms and cleanrooms, the motion that is usually caused by the human mov...

In this study, a realistic model of the respiratory tract obtained from CT medical images was used to solve the flow field and particle motion using the Eulerian–Lagrangian approach to obtain the maximum particle deposition in the bronchial tree for the main purpose of optimizing the performance of drug delivery devices. The effects of different pa...

This study aims to analyze two-phase flow patterns of water and air in a vertical column using experimental tests, and investigate the effect of pulsed gas flow on the characteristics of the Taylor bubble under different inlet conditions. First, three patterns of bubble, slug, and churn were observed with above hundred tests and a flow patterns map...

This research paper delves into the analysis and comparison of two distinct geometries that can be employed to accommodate blocks in the oxygen channel. A fuel cell is an apparatus that generates electricity through the chemical reaction between hydrogen and oxygen, and this form of energy has garnered significant interest from scientists due to it...

In this study, an additional inlet was added to the gas-solid cyclone separator to enhance the separation efficiency. Four different heights were tested, including 0.95D, 1.4D, 1.5D, and 1.95D (D is the diameter of the cylindrical section). The investigation involved two inlet flow conditions: increasing and dividing the inlet flow rate. The finite...

A numerical study on the flow field and particle mixing behavior in spouted beds with the aim of considering different base shapes was carried out using CFD-DEM modeling. Four spouted beds with different base angles of 180, 120, 90 and 60 degrees were compared. In order to have a qualitative and quantitative analysis on the mixing behavior, particl...

This paper explores the effect of curved shape fin heights on open microchannel heat sink performance. Different geometries of rectangular, plano-convex, and plano-concave fins have been investigated by employing three-dimensional simulation. A variety of parameters including fin height, curve range coefficient, Reynolds number, and heat flux have...

The aim of this study is to evaluate the blood rheological behavior within the coronary artery aneurysms in detail. The three-dimensional model was reconstructed from CT-Angiography images of a 43-years-old man with a coronary artery aneurysm on the bifurcation. First, the effects of blood dynamic viscosity on the hemodynamic characteristics in the...

The main purpose of the present numerical study is to evaluate the influences of aneurysm geometric features on the hemodynamic conditions within the left coronary arteries (LCA). Simulations have been conducted in two major parts: Section (I) encompassing three different cases (case 1, case 2, and case 3), in which three various sizes of the bifur...

A comprehensive study using computational fluid dynamics integrated with discrete element method was carried out on spouted beds with different geometries to investigate effects of employing secondary jet inlets with lateral injection to eliminate particle accumulation. Spouted beds with various base angles of 180, 120, 90 and 60 degrees were model...

Inhalation therapy plays an important role in management or treatment of respiratory diseases such asthma and chronic obstructive pulmonary diseases (COPDs). For decades, pressurized metered dose inhalers (pMDIs) have been the most popular and prescribed drug delivery devices for inhalation therapy. The main objectives of the present computational...

Inhalation therapy plays an important role in management or treatment of respiratory diseases such asthma and chronic obstructive pulmonary diseases (COPDs). For decades, pressurized metered dose inhalers (pMDIs) have been the most popular and prescribed drug delivery devices for inhalation therapy. The main objectives of the present computational...

In this paper, fluid flow and heat transfer characteristics in a channel equipped with two isothermal diamond blocks such as blocks filled with PCM’s (during phase changing) to find out the optimum state in fluid flow and heat transfer behavior have been investigated. Different Reynolds and Prandtl numbers and different geometrical parameters such...

Effective drug delivery into the lungs plays an important role in management of pulmonary diseases that affect millions all around the world. The main objective of this investigation is to study airflow structure, as well as transport and deposition of micron-size particles at different inhalation flow rates in a realistic model of human tracheobro...

Effective drug delivery into the lungs plays an important role in management of pulmonary diseases that affect millions all around the world. The main objective of this investigation is to study airflow structure, as well as transport and deposition of micron-size particles at different inhalation flow rates in a realistic model of human tracheobro...

In this paper, pressure drop and change in bulk temperature in a channel with two isothermal blocks have been investigated. Different geometrical parameters have been studied numerically to find the effects of blocks size and position on the flow field and heat transfer. The governing equations, including mass, momentum, and energy conservations, h...

A three-dimensional computational fluid dynamics (CFD) method has been developed to model the flow in the left heart including atrium and ventricle. Since time resolution of the medical scans does not fit the requirements of the CFD calculations, the main challenge in a numerical simulation of heart chambers is wall motion modeling. This study empl...

This paper reviews the application of pulsed flow in fluidized and spouted beds, widely used in various industries. A number of pulsing studies have been performed to improve the performance of these beds, enhance mixing and promote homogeneity. One effective way to increase the efficiency is to pulse the incoming flow, removing inactive or dead zo...

The use of intumescent coating is a tool to cope with fire risks in high-rise buildings and in different industries, increasing of temperature in metal structures and their collapse. This coating is inflated with heat and temperature rise and plays the role of an insulator against thermal penetration into the structure. The use of this tool can del...

Due to increasing application of air conditioning systems in various industries including cleanrooms, the optimized use of the applied equipment for less energy consumption and better contaminant distribution is essential. This paper investigates the effect of four-way ceiling diffuser angle effect on the ventilation system performance numerically...

Effects of variable airflow on particle motion in spout-fluid beds are studied. Computational fluid dynamics using Navier–Stokes equations for the gas phase coupled with the discrete element method using Newton’s laws for the solid phase have been employed. Results indicate that increasing the fluidizing velocity diminishes dead zones and increases...

The effect of flow pulsations is studied via a discrete element model on hydrodynamics of spouted bed, which is being used in many important industries like drying processes. Decreased horizontal air percolation and preserving upward momentum, increased particle circulation, increased particle traverse distance and better homogeneity are resulted f...

The gas-solid flow in a three-dimensional slot-rectangular spouted bed was studied experimentally and numerically. Predictions from the coupled computational fluid dynamics and Discrete Element Method, a powerful numerical approach, are compared with experimental measurements. Flow features inside the slot-rectangular spouted bed were investigated...

The flow behavior and particle motion in a pulsed gas-solid spouted bed was investigated using the Eulerian-Lagrangian approach. The Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) was used to evaluate the gas flow field and particle trajectories. The model was four-way coupled to account for fluid-particle, particle-fluid and partic...

The hydrodynamics of rectangular spout-fluid beds are studied using Computational Fluid Dynamics-Discrete Element Method (CFD-DEM), a powerful approach in simulating gas-solid flows. Modified Navier-Stokes equations for the gas phase mass and momentum balance, and Newton's second law for the solid phase motion are coupled with Newton's third law of...

Studying particle behavior in a spouted bed using Discrete Element Method is the aim of this work. In this study, a numerical simulation using Eulerian-Lagrangian approach is used to solve the Navier-Stokes equations for the gas phase and Newton's laws for the solid phase to investigate the hydrodynamics of gas-solid flow in a spouted bed. The spou...

Flotation of solid particles by means of fluids provides a widely used device known as fluidized bed. The ability of segregation of dissimilar particles due to the difference in their weight and exerted drag force is the motivation of this study to use fluidized bed as a separator. There are different parameters in a fluidized bed which affect the...

In order to evaluate the humidity effect on the performance of a gas-solid cyclone, an experimental setup is designed including a cylindrical cyclone with a tangential inlet, air compressor, humidifier, flow meter and injector of particles with known properties. The cyclone body is a cylinder with diameter and height of 50 and 150 mm, respectively...

Air pulsation effect on the segregation efficiency of mixed binary particles in fluidized beds was studied in this research. Experiments were conducted to investigate pulsed fluidizing effect on two dissimilar sizes of silicon dioxide including flotsam and jetsam particles. A cylindrical bed with 11 cm diameter and 50 cm height was employed to exam...

This study investigates the segregation of dissimilar particles using fluidized bed. A continuous gas-solid fluidized bed with 11 cm inner diameter and 50 cm height is used. Binary particles are Al 2 O 3 powder with two different mean diameters of 150, 470 micron. Effect of inlet airflow rate, initial bed height and volumetric ratio of particles ar...

Lattice Boltzmann method is accepted as an alternative method for classical computational fluid dynamic. It is used in this study to show wave propagation and reflection problem. This method is a good choice of simulating weak acoustic fluctuations. BGK approximation, D2Q9 lattice and bounce back boundary is used to see the behavior of a circular s...

In order to evaluate the separation efficiency and flow field of deoiling hydrocyclones a three dimensional simulation is performed using large eddy simulation (LES) approach. Although this approach has been used in other types of hydrocyclones, the present work is a primer application of the LES approach for simulation of deoiling hydrocyclones. D...

In this paper, numerical simulations are performed to investigate the effect of disturbance block on flow field of the classical square lid-driven cavity. Attentions are focused on vortex formation and studying the effect of block position on its structure. Corner vortices are different upon block position and new vortices are produced because of t...

In this study, the effect of cone angle on the flow field and separation efficiency of deoiling hydrocyclones is investigated taking advantage of large eddy simulation. The dynamic Smagorinsky is employed to determine the residual stress tensor of the continuous phase. The method of Lagrangian particle tracking with an optimized search algorithm (c...

The topic of this research is the importance of convection heat transfer coefficient and the effect that ambient pressure has on it. Toward this end, an experimental study was performed to investigate the effects of air pressure on natural convection heat transfer from a horizontal cylinder. Pressure was varied from 1 to 220 kPa and the convection...

Heat transfer is one of the prevalent concepts with many usages in different fields of science, industry and so on. In different applications we need more or less to know about this phenomenon. Control of this phenomenon is too important in some cases and we should be aware how to control it. The importance of heat transfer rate and effect of vario...