In this paper, we derive mathematical formulas for the skin friction coefficient in wall-bounded turbulence based on Reynolds averaged streamwise momentum equation and total stress. Specifically, with a theoretical or empirical relation of stress, is expressed terms mean velocity shear stress an arbitrary wall-normal region $$[h_0, h_1]$$ . The are validated using direct numerical simulation da...

To calculate the energy costs of swimming or flying, it is crucial to evaluate the drag force originating from skin friction. This topic seems not to have received a definite answer, given the difficulty in measuring accurately the friction drag along objects in movement. The incoming flow along a flat plate in a flapping normal motion has been considered, as limit case of a yawed cylinder in u...

Abstract 3D printing in the textile and fashion industry is a new emerging technology. Applications of for designing clothes other wearable accessories require tribological biological understanding plastics against complex human skin to mitigate skin-friction related ailments such as calluses blisters. This study provides insight search an optimal printable material that has minimal friction sk...

Abrasion of repellent-treated human skin affected the efficacy of a sustained-release insect repellent containing N,N-diethyl-3-methylbenzamide (deet) against bites of Aedes aegypti. Skin treated with repellent when abraded up to 30 times showed significantly lower protection than unabraded skin against mosquito bites for 10 h. The mean value of the kinetic coefficient of friction during skin a...

A detailed investigation of the turbulent boundary layer on a flat plate of finite aspect ratio at zero incidence has been made, incorporating measurements of mean velocity profiles and skin friction over one surface of the plate. Skin friction was measured using Prof. Preston's surface-tube technique with the N.P.L. calibration, and this is justified by comparison with the measured momentum de...

In this paper, we present results obtained by using a numerical procedure for the free convection flow along a rotating nonisothermal plate subject to a nonuniform gravity field. Several specific forms for the temperature distributions of the plate are considered. For these instances the skin-friction and heat transfer rate on the wall at selected values ofthe distance from the leading edge and...

Leg amputees who can't use prostheses and patients with arthritis are often dependent on crutches. Their chronic use can exert significant friction forces. The palmar skin will respond by forming a hyperkeratotic callus. We report for the first time unilateral palmar callus formation caused by friction from using crutches. Another possible adverse effect is the triggering of irritant contact de...