Spatial instability of a wall-bounded flow with fluid injection through porous walls

Download

index.pdf

Date

2019

Author

Köken, Ozan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

149
views

70
downloads

One of the important and yet least understood fields in fluid mechanics research more than a century is hydrodynamic stability. The main objectives in this field are to investigate the breakdown of laminar flows, their subsequent development as the flow evolves along downstream and eventual transition to the fully turbulent flows. The origin of the turbulence and the transition from laminar to turbulent flow is of crucial importance for the whole science of fluid mechanics as well as aviation and marine industries since the flow regime has an impact on the steady operating conditions of many vehicles concerned of those sectors. The focus of the current study is on the stability of an incompressible, homogenous, two-dimensional, planar wall-bounded flow driven by inflow through its porous walls. The non-parallelism of the mean flow and its effect on stability conditions are studied by using two stability approaches, namely, local and nonlocal. Chebyshev collocation method is used to discretize the wall-normal direction, while 1st order-accurate backward difference scheme is used in streamwise marching procedure. Codes for the mean flow calculation, local approach and non-local approach (parabolized stability equations) are written in MATLAB to investigate stability of a non-parallel base flow. Instead of using perturbation of the primitive flow variables, disturbance streamfunction is used in the formulation. The validation of the codes is performed by comparing the numerical results with the literature.

Subject Keywords

Hydrodynamics., Spatial Instability, Hydrodynamic Instability, Parabolized Stability Equations, Non-Parallel Flow Stability, Channel Flow Stability.

URI

http://etd.lib.metu.edu.tr/upload/12624483/index.pdf
https://hdl.handle.net/11511/44633

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Time-space fractional governing equations of one-dimensional unsteady open channel flow process: Numerical solution and exploration Ercan, Ali; Kavvas, M. Levent (2017-07-01) Although fractional integration and differentiation have found many applications in various fields of science, such as physics, finance, bioengineering, continuum mechanics, and hydrology, their engineering applications, especially in the field of fluid flow processes, are rather limited. In this study, a finite difference numerical approach is proposed to solve the time-space fractional governing equations of 1-dimensional unsteady/non-uniform open channel flow process. By numerical simulations, results of...
Numerical Simulation of Rarefied Laminar Flow past a Circular Cylinder Çelenligil, Mehmet Cevdet (2014-07-18) Numerical simulations have been obtained for two-dimensional laminar flows past a circular cylinder in the transitional regime. Computations are performed using the direct simulation Monte Carlo method for Knudsen numbers of 0.02 and 0.2 and Mach numbers of 0.102 and 0.4. For these conditions, Reynolds number ranges from 0.626 to 24.63 and the flows are steady. Results show that separation occurs in the wake region for the flow with Mach number of 0.4 and Knudsen number of 0.02, but for the other eases flow...
Nanotribological properties of the h-BN/Au(111) interface: a DFT study Baksi, Merve; Toffoli, Daniele; Gülseren, Oğuz; Üstünel, Hande (American Chemical Society (ACS), 2019-11-21) Understanding the quantum-mechanical origins of friction forces has become increasingly important in the past decades with the advent of nanotechnology. At the nanometer scale, the universal Amontons-Coulomb laws cease to be valid, and each interface requires individual scrutiny. Because of the well-known lubricating properties of two-dimensional materials, a significant amount of research has been performed in an effort to understand interfaces they form with one another. However, the interfaces between th...
Singularly perturbed diffusion-advection-reaction processes on extremely large three-dimensional curvilinear networks with a periodic microstructure -- efficient solution strategies based on homogenization theory Kropat, Erik; Meyer-Nieberg, Silja; Weber, Gerhard-Wilhelm (American Institute of Mathematical Sciences (AIMS), 2016-8) Boundary value problems on large periodic networks arise in many applications such as soil mechanics in geophysics or the analysis of photonic crystals in nanotechnology. As a model example, singularly perturbed elliptic differential equations of second order are addressed. Typically, the length of periodicity is very small compared to the size of the covered region. The overall complexity of the networks raises serious problems on the computational side. The high density of the graph, the huge number of ed...
Engineering geological characterization of the Antalya karstic rocks, southern Turkey Sopacı, Evrim; Akgün, Haluk (Springer Science and Business Media LLC, 2016-03-01) This study encompasses engineering geological characterization of the Antalya karstic foundation rocks, particularly tufa, whose mechanical behavior is highly variable. The Antalya tufa rock has no well-developed discontinuity systems. It is variably porous, and is composed of different rock types with variable structures. To reveal the engineering geological parameters and to develop a thorough engineering geological database, which is not available in the literature for the Antalya tufa rock, geological o...

Citation Formats

O. Köken, “Spatial instability of a wall-bounded flow with fluid injection through porous walls,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Mechanical Engineering., Middle East Technical University, 2019.