NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Application of turbulence modeling to predict surface heat transfer in stagnation flow region of circular cylinderA theoretical analysis and numerical calculations for the turbulent flow field and for the effect of free-stream turbulence on the surface heat transfer rate of a stagnation flow are presented. The emphasis is on the modeling of turbulence and its augmentation of surface heat transfer rate. The flow field considered is the region near the forward stagnation point of a circular cylinder in a uniform turbulent mean flow. The free stream is steady and incompressible with a Reynolds number of the order of 10 to the 5th power and turbulence intensity of less than 5 percent. For this analysis, the flow field is divided into three regions: (1) a uniform free-stream region where the turbulence is homogeneous and isotropic; (2) an external viscid flow region where the turbulence is distorted by the variation of the mean flow velocity; and, (3) an anisotropic turbulent boundary layer region over the cylinder surface. The turbulence modeling techniques used are the kappa-epsilon two-equation model in the external flow region and the time-averaged turbulence transport equation in the boundary layer region. The turbulence double correlations, the mean velocity, and the mean temperature within the boundary layer are solved numerically from the transport equations. The surface heat transfer rate is calculated as functions of the free-stream turbulence longitudinal microlength scale, the turbulence intensity, and the Reynolds number.
Document ID
19870017728
Acquisition Source
Legacy CDMS
Document Type
Technical Publication (TP)
Authors
Wang, Chi R.
(NASA Lewis Research Center Cleveland, OH, United States)
Yeh, Frederick C.
(NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
September 5, 2013
Publication Date
September 1, 1987
Subject Category
Fluid Mechanics And Heat Transfer
Report/Patent Number
E-3418
NAS 1.60:2758
NASA-TP-2758
Accession Number
87N27161
Funding Number(s)
PROJECT: RTOP 505-62-21
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available