In this paper, the slipping friction is considered in the problem of a progressive wave of real fluids propagating over a permeable bottom.In the interface of soil and fluid, the “no-slip” condition is relaxed and a sliding friction coefficient is introduced. Thus, the slipping effect and the permeability of the bottom on the velocity near the seabed can be studied. The results indicate that th...

This paper presents the results of an experimental study on capillary tubes commonly used as expansion device in household refrigerators and freezers. The experiments were performed with HFC-134a at different condensing pressures and level of subcooling. The pressure and temperature profiles along the capillary tubes were measured in each test run. The data set was then used to evaluate the sui...

-In this work are shown the results obtained from subjecting copper coated with diamond by triboadhesion to a wearing process with a plane rider. Here it is shown the ratio of the normal to shearing forces, called friction factor, as an indication of the resistance of the surface. Micro-Vickers tests shown a 23.2 % increase of hardness of the coated probes compare to non coated probes. Although...

The distribution of the wall shear stress on the bed and sidewalls of an open channel receiving lateral inflow was obtained from experimental measurements of the distribution of the velocity in the viscous sublayer using a laser doppler velocimeter. The experiments were conducted in a 0.4 m wide by 7.5 m long flume. Lateral inflow was provided into the channel from above via sets of nozzles pos...

This paper presents the study of fluid flow and heat transfer in a plain rectangular duct of a solar air heater by using Computational Fluid Dynamics (CFD). The effect of Reynolds number on heat transfer coefficient and friction factor was investigated. A commercial finite volume package ANSYS FLUENT 12.1 is used to analyze and visualize the nature of the flow across the duct of a solar air hea...

coeffcient of  friction  (cof)  for  rubber parts  is one of  the key parameters in their interaction with solid rough surfaces (micrometer to millimeter scales),  such  as  tire-road  interactions. cof  of  rubber  depends  on  viscoelastic properties of rubber, roughness characteristics of the counter-part surface, and process variables such as contact nominal pressure and sliding speed. due ...

Three-dimensional CFD simulations are carried out to investigate heat transfer and fluid flow characteristics of a four-row plain fin-and-tube heat exchanger using the Commercial Computational Fluid Dynamics Code ANSYS CFX 12.0. Heat transfer and pressure drop characteristics of the heat exchanger are investigated for Reynolds numbers ranging from 400 to 2000. Fluid flow and heat transfer are s...

Predictions of the gas temperature and pressure profiles are vital to the design and operation of gas transmission lines. Available analytical methods for the calculation of these profiles are evaluated and a numerical framework for the rigorous calculation has been developed. The predictions from both the analytical and numerical procedure have been compared to field data from the Iranian Gas ...

[1] In the study of natural rivers, accurate conveyance estimation is challenging because of complex cross-sectional geometry and variable flow resistance. The aim of this study was to investigate the additional friction factor due to lateral momentum transfer at the interface of vegetated and nonvegetated channel parts in two rivers: (1) the Rhine River, a large dredged river with partially ve...

We develop a simplified model to predict the frictional behaviour of the contact between the surfaces of a rotary shouldered thread connection in the make-up process of premium tubular connections as used in the oil pipeline business. A classic wear model is applied at the scale of the surface asperities to predict the evolution of friction between initially shot-peened surface and bronze plate...