In this study, the effects of surface roughness differences vehicle coating materials (paint, paste, special applications, etc.) on aerodynamic drag coefficient were inves-tigated using finite element method. For this, forces and aerody-namic coefficients for speeds between 40-150 km/hours calculated a 1/20 scale designed by package program defining body parts front-rear window separately assig...

A surface roughness measurement technique, based on an optical method using a computer vision system, was investigated for applicability to inprocess monitoring of surface quality. The developed vision system uses a CCD camera for scanning gray-scale images from an area of the machined workpiece. This images were analysed with digital image processing system. Some new optical roughness paramete...

Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. It is attributed to the formation of a very thin boundary layer at the absorber plate surface commonly known as viscous sub-la...

An air–sea interaction model that includes turbulent transport due to capillary waves (surface ripples) is developed. The model differs from others in that the physical premises are applicable to low wind speeds (10-m wind speed, U10 , 5 m s21) as well as higher wind speeds. Another new feature of the model is an anisotropic roughness length, which allows a crosswind component of the stress to ...

The Colorado State University standard mesoscale model is used to evaluate the sensitivity of one-dimensional (1D) and two-dimensional (2D) fields to differences in surface-layer parameterization “constants”. Such differences reflect the range in the published values of the von Karman constant, Monin-Obukhov stability functions and the temperature roughness length at the surface. The sensitivit...

Co-plarized of radar backscattering coefficient 0 hh σ and 0 vv σ are estimated for soil surface using a standard theortical model IEM (Integrtion Eequation Model). The surface parameters for model are , dielectric constant and roughness, are determined by experimental technique. The real and imaginary parts ( ε' and ε") of dielectric constant of soil determine by wave guide cell method at a si...

In this study, the Mudan River, which is the most typical river in the northern cold region of China was selected as the research object; Environmental Fluid Dynamics Code (EFDC) was adopted to construct a new two-dimensional water quality model for the urban sections of the Mudan River, and concentrations of COD(Cr) and NH₃N during ice-covered and open-water periods were simulated and analyzed...

Various studies investigating the future impacts of integrating high levels of renewable energy make use of historical meteorological (met) station data to produce estimates of future generation. Hourly means of 10m horizontal wind are extrapolated to a standard turbine hub height using the wind profile power or log law and used to simulate the hypothetical power output of a turbine at that loc...

This paper reports the correlation between film thickness, nanostructure and DC electrical properties of copper thin films deposited by PVD method on glass substrate. X-ray diffraction (XRD) and atomic force microscopy (AFM) were used for crystallography and morphology investigation, respectively. Resistivity was measured by four point probe instrument, while a Hall effects measurement system w...