فهرست مطالب همایون امداد

In this study pressure drop of bin containing corn as granular porous material with two common inlet duct arrangements (H, F) for a laboratory silage was studied by using experimental method. Higher pressure was obtained for the F arrangement compare to the H arrangement. The Ergun equation was fitted on the pressure drop of empirical data and the correction coefficients of modified Ergun equation for both H and F arrangements were determined. The coefficient of determination, mean root square error and mean relative error were used as indices to investigate the goodness of fitness between the empirical data and Ergun equation, and the equation had good fitness on the empirical data. The numerical simulation was carried out by finite element simulation of COMSOL Multiphysics v5.3 software using the modified Ergun equation. Moreover, distribution of velocity and flow lines within the bin was also presented.

Turbinates play an important role in conditioning of inhaled air and affect the air flow passing the nasal cavity. The purpose of this study is to investigate the effect of removing inferior turbinate on flow field, heat and moisture transfer from mucosa into the inhaled-air in a human nasal cavity and comparison of them before and after the surgery. Turbinectomy was performed virtually on the computational model under the specialist’s supervision. In this study the airflow assumed to be laminar and unsteady. The nasal wall assumed to be rigid and no slip boundary condition was set. Moreover, the mucous layer assumed to be within fixed thickness in all over nasal cavity surface. The temperature and humidity distribution over the surface of mucusa are found by numerical computation. The results depict that conditioning of the nasal airway deteriorates by removing the inferior turbinate. For a specific air flow rate, both the heat and moisture flux averages decrease after surgery.

In this paper, optimal control of vortex shedding behind square cylinder in laminar flow regime (Re=200) has been investigated. When Navier-Stokes equations are used as state equations, the discretization of the optimality system leads to large scale discretized optimization problems that represent a tremendous computational task. In order to reduce the number of state variables during the optimization process, a Reduced-Order Model (ROM) based on POD modes is derived to be used as state equations. Then, these equations are modified by introducing a Control Function to ROM in order to gain equations which are suitable for optimal control. Optimal trajectory for control input has been found by employment of Quasi-linearization which is one of the numerical methods for solving optimal control equations. The flow is actuated via suction and blowing slots. The results have been investigated in Results Section.Keywords: Optimal Control- Vortex Shedding- Suction and blowing- Reduced Order Model- POD modes- Quasi-linearization method.