M.J. Maghrebi; A. Zarghami; M. Feyzabadi Farahani
Abstract
The dimensionless Navier-Stokes equation is solved in a rotational form for the flow of a two-dimensional boundary layer of plates by a direct numerical method. Considering the speed profile at the input of the computational domain, the thickness of the boundary layer has been used as the characteristic ...
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The dimensionless Navier-Stokes equation is solved in a rotational form for the flow of a two-dimensional boundary layer of plates by a direct numerical method. Considering the speed profile at the input of the computational domain, the thickness of the boundary layer has been used as the characteristic length and the uniform velocity of the environment has been used as the characteristic velocity for dimensionlessness. The governing differential equations are broken down using the method of finite compression difference in the main directions of the flow and perpendicular to the flow. A forced mapping has been used to convert the physical domain to the computational domain. In order to develop the calculations in the time domain, the third-order compact Ranj Kota method has been used. The output boundary condition is determined using the transfer model. The simulation results of this type of flow are compared with the resolution of Blasius, which shows the accuracy of the code. In this study, the flow characteristics of the quiet boundary layer to evaluate the accuracy of the code, test and by dividing the lengths and velocities by the thickness of the boundary layer and the uniform velocity of the environment, profiles and contours of velocity and vortex in the device of dimensionless coordinates and self-similarity have seen.
science education
M.J. Maghrebi; M. Feyzabadi Farahani; A. Zarghami
Abstract
Theories of linear stability, reinforcement, or degradation of small disturbances examine the velocity applied to the average velocity of the flow. When the boundary layer flow expands linearly in the early stages of its development, the input boundary conditions of the computational domain are determined ...
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Theories of linear stability, reinforcement, or degradation of small disturbances examine the velocity applied to the average velocity of the flow. When the boundary layer flow expands linearly in the early stages of its development, the input boundary conditions of the computational domain are determined using the results of the linear stability solution. In order to better adapt to laboratory results, spatial stability analysis is used. Using an algebraic mapping, the physical domain is converted to a computational domain. To solve the Or-Samerfeld equation, a spectral method has been used that has led to the solution of a special value problem. Comparing laboratory results and results of spatial and temporal perturbation stability analysis, it can be stated that spatial perturbation growth analysis more accurately describes the instability characteristics of the perturbation boundary flow. Small frequencies are much more accurate.
