Doctoral Dissertations


Jen-Tai Lin


"Mixed convective heat transfer results for two-dimensional laminar/turbulent flow in a duct with a backward-facing step are reported. The two walls forming the duct are maintained at uniform but different temperatures. The straight wall is maintained at the inlet air temperature, while the downstream section of the stepped wall is heated to a higher temperature. This study focuses on a backward-facing step geometry with an expansion ratio of two. The present laminar study examines a wide range of inlet flow and wall temperature conditions to cover the domain from buoyancy-assisting mixed convective flow, pure forced convective flow, buoyancy-opposing mixed convective flow to the inlet starved convective flow. Turbulent mixed convective flow is numerically simulated by using a modified k - ε model. For the buoyancy-assisting laminar flow, the buoyancy force reduces the pressure drop across the duct along with the reattachment length and increases the heat transfer rate. The reverse of previous trend applies for the buoyancy-opposing flow condition. A larger buoyancy force in buoyancy-assisting turbulent flow will decrease turbulent kinetic energy, increase the dissipation rate of turbulent kinetic energy, thus causing reattachment length to increase and the heat transfer rate to decrease. The numerical predictions are compared very favorably with existing, but limited, experimental and numerical data"--Abstract, page iv.


Armaly, B. F. (Bassem F.)
Chen, T. S.

Committee Member(s)

Bolon, Albert E., 1939-2006
Tsoulfanidis, Nicholas
Lee, S. C.


Nuclear Engineering and Radiation Science

Degree Name

Ph. D. in Nuclear Engineering


University of Missouri--Rolla

Publication Date

Spring 1989

Journal article titles appearing in thesis/dissertation

  • Mixed convection in buoyancy-assisting, vertical backward-facing step flows
  • Mixed convection heat transfer in inclined backward-facing step flows
  • Buoyancy-opposing mixed-convection heat transfer in inclined backward-facing step flows
  • Turbulent mixed convection in a vertical duct with a backward-facing step


xii, 143 pages

Note about bibliography

Includes bibliographical references.


© 1989 Jen-Tai Lin, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 5869

Print OCLC #