Investigation of Incompressible ROUCH-WALL boundary Layer Flows.(Dept.M)

Berge Djebedjian,Samir Hanna

doi:10.21608/bfemu.2021.171895

Abstract

COLES [1] suggested to represent the velocity distribution in turbulent boundary layers with adverse pressure gradient over smooth surface by a linear combination of two universal functions.one is the well known law of the wall, the other the law of the wake which is characterised by the profile at a point of separation or reattachment. The aims of this investigation are to modify Coles velocity distribution to perform the calculations for turbulent boundary layers over smooth and rough surfaces and also to study analytically the various boundary layer parameters and surface roughness function derived from the modified velocity distribution and experimental results with flows over rough surfaces given in [10].

Highlights

Elecityof the fluid inside rhe boundary layer 'n lIi-direcriOr'l "e-loci ty component inStde the boundary layer in y-eirectlon lurf:>ce rou~hne~~ fune tlon
Solulion ot boundary layer probLems depends on the velocity distribution and whether th~ How is laminar or turbulent. 01 the twO, the laminar boundary layer is more amenable to analytical solution and th~re is an elttensive literature on laminar boundary I~yer al me
(J) The surface rou~hne[55] funcllon, Clc _. kl j.i ljLor the boundary layer with the same rallo of k/6" and the roughness helghr,l Rekjlncrea.ses wirh the increase of both Euler number

Summary

Introduction

Elecityof the fluid inside rhe boundary layer 'n lIi-direcriOr'l "e-loci ty component inStde the boundary layer in y-eirectlon lurf:>ce rou~hne~~ fune tlon. ....elecityof the fluid inside rhe boundary layer 'n lIi-direcriOr'l Solulion ot boundary layer probLems depends on the velocity distribution and whether th~ How is laminar or turbulent. The :ast term 0/ equa I i~n (2.2, J), represenlS the sur {ace

Results

Conclusion