I N T R 0 D U C T I 0 N In recent years, the application of double-flow rotary vane compressor in automotive air-conditioning systems has been increased because of its multiple cylinder characteristic. A certain problem is its high friction loss at higher speeds. The greatest amount of the friction is caused by the lubrication systems between the vane tip and the cylinder wall and between vane ...

Abstract—The presence of bubbles in the boundary layer introduces corrections into the log law, which must be taken into account. In this work, a logarithmic wall law was presented for bubbly two phase flows. The wall law presented in this work was based on the postulation of additional turbulent viscosity associated with bubble wakes in the boundary layer. The presented wall law contained empi...

the present paper investigates turbulent mixed convection - radiation flow between two vertical parallel plates kept at different temperatures with variable thermophysical properties. the reynolds number, based on channel half-width and friction velocity and the grashof number, based on channel width and wall temperature difference, were assumed to be 150 and 1.6×106, respectively. numerical si...

A spanwise array of surface hot-film shear-stress sensors and a traversing hot-wire located directly above one of these sensors are used to examine the relationship between skin-friction fluctuations and the velocity fluctuations in the boundary layer. Experiments are performed in a high Reynolds number turbulent boundary layer at Reθ ≈ 39000. The shear-stress data indicate the presence of larg...

failure of the quay walls due to earthquakes results in severe economic loss. because of hazards threatening such inexpensive nodes of national and international transportation networks, seismic design of quay walls is still an evolving topic in marine structural engineering. this study investigates the sensitivity of the gravity-type quay wall stability respect to uncertain soil and seismic pr...

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...

[1] Near the bottom, the velocity profile in the bottom boundary layer over the continental shelf exhibits a characteristic law-of-the-wall that is consistent with local estimates of friction velocity from near-bottom turbulence measurements. Farther from the bottom, the velocity profile exhibits a deviation from the law-of-the-wall. Here the velocity gradient continues to decrease with height ...

calculation of lateral earth pressure on retaining walls is one of the main issues in geotechnics. the upper and lower bound theorems of plasticity are used to analyze the stability of geotechnical structures include bearing capacity of foundations, lateral earth pressure on retaining walls and factor of safety of slopes. in this paper formulation of finite element limit analysis is introduced ...

The paper presents near-wall scaling in incompressible and compressible flows. It concentrates on flows with streamwise pressure gradients which render traditional scaling inapplicable. For incompressible flows a scaling for the velocity profiles is introduced based on both the friction velocity and the pressure gradient. For compressible flows a scaling is developed for the velocity and the te...