چکیده مقاله
Fluid turbulence plays a critical role in many natural and engineering systems, yet directly solving the complete Navier–Stokes equations to capture all turbulent scales remains computationally expensive, especially for complex domains and high Reynolds numbers This study investigates the artificial generation and downstream propagation of vortical structures in an incompressible two dimensional channel flow using Direct Numerical Simulation DNS at a Reynolds number of 200 The main purpose is to examine whether a controlled inlet disturbance can reproduce early stage transitional flow features without requiring the long computational domain usually needed for natural boundary layer transition A time dependent periodic perturbation is imposed at the channel inlet, while the governing equations are discretized using a fourth order compact finite difference scheme in space and advanced in time by a third order Runge–Kutta method The computations are performed on an algebraically stretched 240 × 80 grid, with refined nodes near the lower boundary layer to improve the resolution of high gradient regions The results show the formation, shedding, and downstream convection of localized vortex structures along the channel wall Velocity and pressure fields indicate that the inlet disturbance generates coherent unsteady motion and localized pressure variations associated with vortex cores The findings suggest that the perturbation amplitude and fluid viscosity have stronger effects on the initiation and development of vortical structures than the excitation frequency alone Overall, the study demonstrates the usefulness of artificial inlet excitations for investigating controlled transitional flow structures with manageable computational cost
کلیدواژهها
نویسندگان
Ali Karimi
School of Mechanical Engineering, Shiraz University, Shiraz, Iran
Ali Karimi
School of Mechanical Engineering, Shiraz University, Shiraz, Iran
Amir Mohammad Saadat
Department of Water Engineering and Management, Tarbiat Modares University, Tehran, Iran
Amir Mohammad Saadat
Department of Water Engineering and Management, Tarbiat Modares University, Tehran, Iran
شیوه ارجاع
Karimi, Ali and Saadat, Amir Mohammad,1405,DIRECT NUMERICAL SIMULATION OF ARTIFICIALLY INDUCED BOUNDARY LAYER TURBULENCE AND VORTEX PROPAGATION IN A 2D CHANNEL,20th International Conference on Mechanical, Construction Industrial & Civil Engineering
ارائهشده در
مجموعه مقالات بیستمین کنفرانس بین المللی مکانیک، ساخت، صنایع و مهندسی عمران24 اردیبهشت 1405