Date of Award

1-31-1993

Document Type

Thesis

Degree Name

Master of Science in Mechanical Engineering - (M.S.)

Department

Mechanical and Industrial Engineering

First Advisor

Anthony E. Cerkanowicz

Second Advisor

Rong-Yaw Chen

Third Advisor

Robert P. Kirchner

Abstract

Catalytic combustion/incineration is becoming increasingly important in modern industrial processes. This thesis work investigates the importance of heat and mass transfer entrance effects in short catalytic combustion monoliths, and includes these effects in an engineering model. Consideration is limited to laminar-flow heat and mass transfer in a circular tube, in which Prandtl number is close to unity, as is the case for air. Thermal, mass and velocity boundary layer growths are considered with inlet conditions assumed uniform at a monolith bed entrance. Conservation equations are solved assuming laminar, steady-state flow, with constant wall temperature, and negligible axial diffusion of heat and mass. The results compare fuel conversion with and without consideration of entrance effects. At low inlet temperature, inclusion of entry effects results in higher fuel conversion that due to increased mass transport. However, for high inlet temperature, the entry length effects make a negative contribution to surface temperature due to increased heat transport, thus decreasing the conversion rate. Finally, turbulent flow conditions are discussed with the conclusion of decreased importance of the entrance length region.

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