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Algorithm for equilibrium transit assignment problem
, Article Transportation Research Record ; Issue 1923 , 2005 , Pages 227-235 ; 03611981 (ISSN) ; Aashtiani, H. Z ; Sharif University of Technology
National Research Council
2005
Abstract
Transit assignment is an important problem in the literature of transportation. Almost all competitive algorithms in this area are strategy based. For uncongested transit networks, the problem may be formulated into an optimization problem for which good solution algorithms exist. A variational inequality formulation of the problem with several solution methods is also presented in the literature for congested networks. This paper is devoted to solving a transit assignment problem based on complementarity formulation using path flows. The solution algorithm exploits the three concepts of decomposition, path generation, and linearization. The procedure has been applied on a large-scale...
Application of Micro Combustion In Boundary Layer Control
, M.Sc. Thesis Sharif University of Technology ; Javadi, Khodayar (Supervisor) ; Mardani, Amir (Co-Advisor)
Abstract
The present study focus is on finding a new solution to control laminar separation bubble phenomenon by combustion actuators in micro scale, which is investigated in flows with low Reynolds number surface effect and free flows. The main parameters in this problem are classified in three groups of formation location of laminar separation bubble, its length, and transition from laminar to turbulent around airfoil SD8020 in attack angle of 5 and 8 degree. Following that, the new combustion actuators in micro scale method the comparison it with cold (and hot) air jet injection is introduced to control boundary layer flow with separation bubble point of view. Some mechanisms are identified in...
Torque data on non-isothermal rarefied Cylindrical Couette flow
, Article Vacuum ; Volume 121 , November , 2015 , Pages 56-63 ; 0042207X (ISSN) ; Javadi, K ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Abstract The torque exerted on the walls of a micro cylindrical Couette gas flow is studied using Direct Simulation Monte Carlo (DSMC) method and analytical solutions. An analytical solution for temperature filed under specified wall heat flux condition is proposed using a previously introduced power-law (PL) wall-scaling approach. The results of cylindrical Couette flow under specified wall heat flux condition are compared with those of isothermal flow. The effects of rarefaction, compressibility, tangential momentum accommodation coefficient (TMAC) and gas-surface heat exchange on the torque values are investigated for slip to free molecular flow regimes. The results indicate that the...
Extending the Navier-stokes solutions to transition regime in two-dimensional micro- and nanochannel flows using information preservation scheme
, Article Physics of Fluids ; Volume 21, Issue 8 , 2009 ; 10706631 (ISSN) ; Darbandi, M ; Sharif University of Technology
2009
Abstract
The kinetic-theory-based numerical schemes, such as direct simulation Monte Carlo (DSMC) and information preservation (IP), can be readily used to solve transition flow regimes. However, their high computational cost still promotes the researchers to extend the Navier-Stokes (NS) equations beyond the slip flow and to the transition regime applications. Evidently, a suitable extension would accurately predict both the local velocity profiles and the mass flow rate magnitude as well as the streamwise pressure distribution. The second-order slip velocity model derived from kinetic theory can provide relatively accurate velocity profiles up to a Knudsen (Kn) number of around 0.5; however, its...