Calculation of skin-friction coefficients for low-Reynolds-number turbulent boundary layer flows

Technical Report · Tue Jan 01 04:00:00 EST 1980

OSTI ID:5502424

Barr, P K

An analysis is presented of the reliability of various generally accepted empirical expressions for the prediction of the skin-friction coefficient C/sub f/ of turbulent boundary layers at low Reynolds numbers in zero-pressure-gradient flows on a smooth flat plate. The skin-friction coefficients predicted from these expressions were compared to the skin-friction coefficients of experimental profiles that were determined from a graphical method formulated from the law of the wall. These expressions are found to predict values that are consistently different than those obtained from the graphical method over the range 600 < Re/sub theta/ < 2000. A curve-fitted empirical relationship was developed from the present data and yields a better estimated value of C/sub f/ in this range. The data, covering the range 200 < Re/sub theta/ < 7000, provide insight into the nature of transitional flows. They show that fully developed turbulent boundary layers occur at Reynolds numbers Re/sub theta/ down to 425. Below this level there appears to be a well-ordered evolutionary process from the laminar to the turbulent profiles. These profiles clearly display the development of the turbulent core region and the shrinking of the laminar sublayer with increasing values of Re/sub theta/.

• Research Organization: Sandia Labs., Albuquerque, NM (USA); Sandia Labs., Livermore, CA (USA)
• DOE Contract Number: EY-76-C-04-0789
• OSTI ID: 5502424
• Report Number(s): SAND-79-8062
• Country of Publication: United States
• Language: English

Related Subjects

640410* -- Fluid Physics-- General Fluid Dynamics
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOUNDARY LAYERS
COMPUTERIZED SIMULATION
FLUID FLOW
FLUID MECHANICS
FRICTION FACTOR
LAMINAR FLOW
LAYERS
MECHANICS
NUMERICAL SOLUTION
PLATES
REYNOLDS NUMBER
SIMULATION
TURBULENT FLOW