Receptivity mechanism of bypass transition subject to synthesized freestream turbulence

Name: Chate Pongudom

LCSH: Kasetsart University -- Theses. M.Eng. (Aerospace Engineering) 2017

Classification :.LCCS: TL574.T8

LCSH: Kasetsart University. Department of Aerospace Engineering -- Theses

LCSH: Turbulence

LCSH: Turbulent boundary layer

Abstract: Transitional boundary layer plays an important role in many flow applications such as a modern turbomachinery. The mechanism amongs laminar to turbulent flow seems to mystrious therefore this field of interest is approached by many studies. Increasing in Reynolds number brings about an obscure mechanism in transition region. Numerical simulation is one of an effective tool that can deal with these complex scenarios. This study uses a benefit of a Computational Fluid Dynamics (CFD) commercial program to investigate the outcome. A zero pressure gradient flat plate boundary layer with a leading edge is simulated on a three dimensional rectangular box domain. Large Eddy Simulation (LES) technique with a Kinetic Turbulent Energy as the Subgrid Scale model (SGS) is used. The main purpose of this study is to investigate the receptivity mechanism of the synthesized freestream turbulence compared to the natural freestream turbulence. Freestream Turbulence (FST) is artificially generated by a vortex method. Selection of interested parameters as its inflow condition, Turbulent intensity (Tu) and Length scale (L) have an influential impact on the bypass transition receptivity mechanism. Skin friction coefficient is a one most important indicator gives an evidence of the transition onset and the completion to this study. Turbulent spot is observed and shown via a visualisation. Increasing in a turbulent intensity tends to strenghten Klebanoff modes and early provokes turbulent spots resulting in moving the turbulent spot upstream. So as the length scale seems to enhance a spot production leads to an abridgement in a transition length.

Kasetsart University. Office of the University Library

Address: Bangkok

Email: tdckulib@ku.ac.th

Name: Vejapong Juttijudata

Role: Thesis Advisor

Created: 2017

Modified: 2568-07-01

Issued: 2023-06-01

วิทยานิพนธ์/Thesis

application/pdf

URL: https://kasetsart.idm.oclc.org/login?url=https://www.lib.ku.ac.th/KUthesis/2560/chate-pon-all.pdf

CallNumber: TL574.T8.C43

eng

DegreeName: Master of Engineering

Level: Master's Degree

Descipline: Aerospace Engineering

Grantor: Kasetsart University

©copyrights Kasetsart University

ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	chate-pon-all.pdf	2.62 MB

ใช้เวลา

0.033182 วินาที