A Caltech Library Service

I. Laminar Boundary Layer Stability in Free Convection. II. Laminar Free Convection with Variable Fluid Properties


Plapp, John Elmer (1957) I. Laminar Boundary Layer Stability in Free Convection. II. Laminar Free Convection with Variable Fluid Properties. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/6DDP-8W66.


I. LAMINAR BOUNDARY LAYER STABILITY IN FREE CONVECTION The stability with respect to transition to turbulent flow of laminar free convection flow along a semi-infinite flat plate was studied analytically by the method of small oscillations. Six procedures of varying degrees of mathematical complexity for solving approximately the stability problem were developed according to different assumptions regarding the presence or absence of heat conduction and viscous and body forces. The procedure which considers that only inertial, pressure, and viscous forces control the stability was applied to the case of free convection of air along a vertical plate. It was found that the analytic predictions agreed qualitatively but not quantitatively with experimental observations made by other investigators of the appearance of instability in such a flow. II. LAMINAR FREE CONVECTION WITH VARIABLE FLUID PROPERTIES Heat transfer by laminar free convection along a semi-infinite flat plate was analyzed with the assumption that the density, specific heat, viscosity, and thermal conductivity of the fluid are functions of the temperature. An approximate method for obtaining heat-transfer rates was developed and was applied to cases of heating and cooling oils with large changes in their Prandtl numbers. By comparison, it was found that earlier and more general analyses based on essentially constant-property assumptions give good results in the variable-property case when they are based on the properties of the fluid at the plate surface.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Mechanical Engineering and Physics)
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Mechanical Engineering
Minor Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Rannie, W. Duncan
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1957
Record Number:CaltechETD:etd-09142004-153230
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3527
Deposited By: Imported from ETD-db
Deposited On:15 Sep 2004
Last Modified:12 Oct 2023 18:22

Thesis Files

PDF (Plapp_je_1957.pdf) - Final Version
See Usage Policy.


Repository Staff Only: item control page