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The air-cooled engine surfaces are generally provided with extended surfaces of high conducting materials called fins for enhanced heat transfer. One way to increase the rate of heat transfer is by increasing the fins surface area. However, increase in fin length introduces undesirable vibrations of the fins, which in turn radiate annoying high frequency noise. With the demand of quieter engines increasing, the vehicle manufacturers follow counter measures to minimize the fin vibrations. One trend in the two-wheeler industry is to put rubber dampers between the fins. These rubber dampers...
The differential equation for dilute species transport next to a planar interface within the hydrodynamic boundary layer is transformed into a differential equation for the diffusion boundary layer. This differential equation contains two coefficients, which depend explicitly on the concentration profile. We show that these coefficients can be taken as identical constants, in a number of limiting cases. Using these constants, we show that this equation reproduces very well the temporal and spatial profile of the diffusion boundary layer determined from numerical simulations in some more...
One of the common causes of premature tube failure in fired tube boilers - technically described as film boiling - is overheating of the tubes caused by steam blanketing. Current literature contains a significant amount of information on this problem, but not much in the way of definitive guidance for avoiding the problem. General “rules of thumb” are available for identifying the heat flux limit required to avoid the problem as in Martens et al . Unfortunately, the values presented by different sources are often in disagreement. This paper will look at a sulfur recovery unit (SRU) Claus...
This paper investigates the first part of a two-stage methodology for the detailed fully coupled modelling of nanoparticle formation in turbulent reacting flows. We use a projected fields (PF) method to approximate the joint composition probability density function (PDF) transport equation that describes the evolution of the nanoparticles. The method combines detailed chemistry and the method of moments with interpolative closure (MoMIC) population balance model in a commercial computational fluid dynamics (CFD) code. We show details of the implementation and present an extensive set of...
The effects of a typical glaze ice accretion shape on the performance of the M2129 S-duct inlets are computationally investigated using the steady-state RANS solution. The glaze ice accreted on the inlet lip causes a significant degradation in the inlet performance, and the degradation is enhanced as free-stream Mach numbers increase. With increasing freestream Mach numbers from M =0.13 to 0.85, total pressure recovery decreases from 0.985 to 0.61. And the level of the mass flow rate with the glaze ice accretion is 73 percent of that in the ice-free condition at M =0.13; however, it decreases...
Computational fluid dynamics models of wind-dominated and wind and buoyancy-influenced ventilation in a naturally ventilated livestock building were developed to investigate the mixing characteristics of the building and to determine its ventilation efficiency when different cladding materials are used at the eave openings. Firstly, CFD was used to provide insight into the air mixing characteristics of the building during wind-driven and wind and buoyancy-influenced ventilation. Secondly the relationship between an eave opening’s resistance to airflow and indoor air mixing during wind-...
The flow inside a combustion engine is highly complex and varies significantly with small changes in the engine configuration. For a long time IC-engine researchers have tried to predict the major mean flow patterns inside close-to-production engine setups. During the last decades computational fluid dynamics (CFD) has significantly contributed to the engine development process. Hence, significant research has focussed on the comparison of modeled and measured flows in IC engines. However, according to the knowledge of the authors, this study is the first fully three-dimensional (3-D),...
This paper reports on methods for the analysis of electrical machines by combined electromagnetic and thermal models using commercial software which can be an aid to the design of these machines. Examples using a brushless permanent-magnet motor and an induction motor illustrate the tools available and techniques possible.
With an ever increasing energy crisis occurring in the world it will be important to investigate alternative methods of generating power in ways different than, fossil fuels. In fact, one of the biggest sources of energy is all around us all of the time, the wind. It can be harnessed not only by big corporations but by individuals using Vertical Axis Wind Turbines (VAWT). VAWT’s offer similar efficiencies as compared with the horizontal axis wind turbines (HAWT) and in fact have several distinct advantages. One advantage is that unlike their HAWT counterparts, they can be placed independently...

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