RIBLET MODELING USING A 2ND-MOMENT CLOSURE

A low Reynolds number second-moment closure has been used to calculate a turbulent boundary layer which develops over a riblet surface with zero pressure gradient. The calculated mean velocity distributions com pare favourably with measurements. Calculated Reynolds stresses away f rom the riblet surface region are also in agreement with measurements. In the vicinity of the riblets, the model reflects the increased anis otropy of the Reynolds stress tenser inadequately. Possible reasons fo r this shortcoming are discussed and suggestions for improving the mod el are made.