Heat transfer enhancement by a multilobe vortex generator in internally finned tubes

Journal Article · Thu Apr 01 04:00:00 EST 1999 · Numerical Heat Transfer. Part A, Applications

OSTI ID:357704

Tsui, Y Y; Leu, S W ^[1]

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1. National Chiao Tung Univ., Hsinchu (Taiwan, Province of China). Dept. of Mechanical Engineering

A three-dimensional computational method is employed to study the flow and heat transfer in internally finned tubes with a multilobe vortex generator inserted. Governing equations are discretized using the finite volume method. The irregular lobe geometry is treated using curvilinear nonstaggered grids. The linear interpolation method is adopted to calculate face velocities. The results show that secondary flows induced by the lobes are transformed to become axial vortices downstream of the vortex generator. As a consequence of the transport by the vortex flow, the core flow is moved to the fins and the tube wall, while the wall flow moves to the core. In this way, both heat transfer and flow mixing are enhanced. When the fin height is increased, the axial vortex is more restricted in the centerline region, and the strength of the vortex flow, represented by circulation, is decreased. In turn, the total pressure loss is also decreased. However, the heat transfer increases with fin height. Consequently, efficiency is greatly promoted.

• OSTI ID: 357704
• Journal Information: Numerical Heat Transfer. Part A, Applications, Journal Name: Numerical Heat Transfer. Part A, Applications Journal Issue: 5 Vol. 35; ISSN NHAAES; ISSN 1040-7782
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
AUGMENTATION
HEAT EXCHANGERS
HEAT TRANSFER
MESH GENERATION
NUMERICAL SOLUTION
PERFORMANCE
THREE-DIMENSIONAL CALCULATIONS
VORTICES