Experimental investigation of two-phase flow phenomena in horizontal convective in-tube boiling system

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)


Mechanical Engineering

First Committee Member

Sadik Kakac, Committee Chair


The objective of this study was to investigate experimentally the thermal and hydrodynamic behavior, and dynamic instability in two-phase flow associated with refrigerant-11 in a uniformly heated horizontal in-tube convective boiling system.The experimental set-up used in this study was designed and built by the author. The test section was placed horizontally, and the stainless steel heater tubes were heated uniformly by a DC power source.Two major parts of experimental work were conducted: (1) Two-phase flow stratification due to gravity effects, and consequently its thermal and hydrodynamic behavior in a single horizontal tube under steady state conditions, was determined by measuring the top and bottom wall temperatures. A dimensionless number was found for the prediction of the occurrence of different flow patterns (Chapter 5). (2) Two-phase flow dynamic instabilities in a single tube configuration were found to bear similarities to vertical upflow systems. It was concluded however, that the entire unstable region was shifted to the right, compared to vertical flow, on the steady state characteristic plane (Chapter 6). Another important part of the work done was the application of dimensional analysis towards the steady state characteristic curves conventionally plotted in a $\Delta$P-G plane (Chapter 7). An infinite number of curves corresponding to different heat inputs could be converted to a single curve in a new coordinate system represented by two dimensionless numbers. PI theorem was used to perform this analysis.


Engineering, Mechanical

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