Study on Hydrodynamic Coefficients of Double Submerged Inclined Plates

Added mass and damping coefficients are very important in hydrodynamic analysis of naval structures. In this paper,a double submerged inclined plates with ‘/\’ configuration is firstly considered. By use of the boundary element method(BEM) based on Green function with the wave term, the radiation problem of this special type structure is investigated. The added mass and damping coefficients due to different plate lengths and inclined angles are obtained. The results show that: the added mass and damping coefficients for sway are the largest. Heave is the most sensitive mode to inclined angles. The wave frequencies of the maximal added mass and damping coefficients for sway and roll are the same.

Chemical Reaction and Thermal Diffusion Effects on Mass Transfer Flow through an Inclined Plate

A numerical investigation of boundary layer mass transfer flow through an inclined plate with the effect of chemical reaction and thermal diffusion is presented in this study. The governing partial differential equations (PDE) are transformed to a system of dimensionless non-similar coupled PDEs. The transformed, non-similar conservations equations (momentum balance equation, energy balance equation and concentration balance equation) are then solved using a numerical approach known as explicit finite difference method (EFDM). Basically EFDM introduced for the unsteadiness in the momentum, temperature, and concentration fluid fields is based on the time dependent fluid velocity, temperature and concentration of the boundary surface. During the course of discussion, it is found that the various parameters related to the problem influence the calculated resultant expressions. The computed numerical solution results for the velocity, temperature, and concentration distribution with the effect of various important dimensionless parameters (Grashof number, Modified Grashof number, Prandtl number, Schmidt number, Soret number, Dufour number, chemical reaction parameter and inclination parameter) entering into the problems are critically analyzed and discussed graphically. It can be seen that two physical phenomena chemical reaction and thermal diffusion can greatly effect on the boundary layer fluid flows through an inclined plate.

Optimizing the seed-cell filling performance of an inclined plate seed metering device using integrated ANN-PSO approach

Uniformseed distribution within the row is the prime objective of precision planters for better crop growth and yield.Inclined plate planters are generally used for sowing bold seeds likemaize,groundnut,chickpea,and their operating parameters like the forward speed of operation,the seedmetering plate inclination,and the seed level in the hopper affect the cell fill and subsequently the uniformseed distribution.Therefore,to achieve precise seed distribution,these parameters need to be optimized.In the present study,out of the different optimization techniques,a new intelligent optimization technique based on the integrated ANN-PSO approach has been used to achieve the set goal.A 3–5-1 artificial neural network(ANN)model was developed for predicting the cell fill of inclined plate seedmetering device,and the particle swarmoptimization(PSO)algorithmwas applied to obtain the optimum values of the operating parameters corresponding to 100%cell fill.The most appropriate optimal values of the forward speed of operation,the seed metering plate inclination,and the seed level in the hopper for achieving 100%cell fill were found to be 3 km/h,50-degree,and 75%of total height,respectively.The proposed integrated ANN-PSO approach was capable of predicting the optimal values of operating parameters with amaximumdeviation of 2%compared to the experimental results,thus confirmed the reliability of the proposed optimization technique.

Thermal criticality for a reactive gravity driven thin film flow of a third-grade fluid with adiabatic free surface down an inclined plane

This study is devoted to the investigation of thermal criticality for a reactive gravity driven thin film flow of a third-grade fluid with adiabatic free surface down an inclined isothermal plane. It is assumed that the reaction is exothermic under Arrhenius kinetics, neglecting the consumption of the material. The governing non-linear equations for conservation of momentum and energy are obtained and solved by using a new computational approach based on a special type of Hermite-Padé approximation technique implemented in MAPLE. This semi-numerical scheme offers some advantages over solutions obtained with traditional methods such as finite differences, spectral method, and shooting method. It reveals the analytical structure of the solution function. Important properties of overall flow structure including velocity field, temperature field, thermal criticality, and bifurcations are discussed.

Influence of melt pouring temperature and plate inclination on solidification and microstructure of A356 aluminum alloy produced using oblique plate

The preparation of semisolid slurry of A356 aluminum alloy using an oblique plate was investigated. A356 alloy melt undergoes partial solidification when it flows down on an oblique plate cooled from underneath by counter flowing water. It results in continuous formation of columnar dendrites on plate wall. Due to forced convection, these dendrites are sheared off into equiaxed/fragmented grains and then washed away continuously to produce semisolid slurry at plate exit. Melt pouring temperature provides required condition of solidification whereas plate inclination enables necessary shear for producing semisolid slurry of desired quality. Slurry obtained was solidified in metal mould to produce semisolid-cast billets of desired microstructure. Furthermore, semisolid-cast billets were heat treated to improve surface quality. Microstructures of both semisolid-cast and heat-treated billets were analyzed. Effects of melt pouring temperature and plate inclination on solidification and microstructure of billets produced using oblique plate were described. The investigations involved four different melt pouring temperatures (620, 625, 630 and 635 °C) associated with four different plate inclinations (30°, 45°, 60° and 75°). Melt pouring temperature of 625 °C with plate inclination of 60° shows fine and globular microstructures and it is the optimum.

Neuroprotective effects of the immunomodulatory drug Setarud on cerebral ischemia in male rats

immunomodulary drug Setarud, which is composed of herbal extracts including Rosa canina, Urtica dioica and Tanacetum vulgare, supplemented with selenium exhibits anti-inflammatory and anti-oxidant properties. Therefore, we hypothesized that Setarud will have a neuroprotective effect against ischemic cerebral injury. To validate this hypothesis, rats were intraperitoneally administered with 0.66 mL/kg Setarud for 30 minutes after middle cerebral artery occlusion. Triphenyltetrazolium chloride staining showed that Setarud could reduce cerebral infarct volume of rats subjected to cerebral ischemia. Transmission electron microscopy and hematoxylin-eosin staining results showed that Setarud could alleviate the degenerative changes in cortical neurons of rats with cerebral ischemia. The inclined plate test and prehensile test showed that Setarud could significantly improve the motor function of rats with cerebral ischemia. These findings suggest that Setarud shows neuroprotective effects against ischemic brain injury.

Lubrication characteristics of external return spherical hinge pair of axial piston pump or motor under combined action of inclination and offset distance

External return mechanism is a mechanical structure applied to axial piston pumps.To study its lubrication characteristics,the Reynolds equation applied to an external return spherical hinge pair was deduced based on the vector equation of relative-motion velocity of the external return spherical hinge pair under the influence of external swash plate inclination and offset distance.The results show that the total friction,axial leakage flow,and maximum value of the maximum oil-film pressure increase with increasing pump-shaft speed and decrease with increasing offset distance in one working cycle when the external-swash-plate inclination is constant.However,the varying offset distance has little effect on the axial leakage flow.The maximum value of the maximum oil-film pressure decreases with increasing external-swash-plate inclination and the total leakage flow increases with increasing external-swash-plate inclination in one working cycle when the offset distance is constant.It can be seen that the abovementioned parameters are important factors that affect the lubrication characteristics of external return spherical hinge pairs.Therefore,the complex effects of different coupling parameters should be comprehensively considered in the design of the external return mechanism.

Modeling natural convection heat transfer from perforated plates

Staggered pattern perforations are introduced to isolated isothermal plates,vertical parallel isothermal plates,and vertical rectangular isothermal fins under natural convection conditions.The performance of perforations was evaluated theoretically based on existing correlations by considering effects of ratios of open area,inclined angles,and other geometric parameters.It was found that staggered pattern perforations can increase the total heat transfer rate for isolated isothermal plates and vertical parallel plates,with low ratios of plate height to wall-to-wall spacing(H/s),by a factor of 1.07 to 1.21,while only by a factor of 1.03 to 1.07 for vertical rectangular isothermal fins,and the magnitude of enhancement is proportional to the ratio of open area.However,staggered pattern perforations are detrimental to heat transfer enhancement of vertical parallel plates with large H/s ratios.