Papers by Keyword: Geometric Parameter

Abstract: A study of the heat transport and fluid flow behaviour around a tilted elliptical cylinder that is located concentrically in a square enclosure whose top horizontal wall is driven by a lid in the positive x-direction is presented. Due to the disparities in the results of convective heat transfer in square cavities in the literature, this study seeks to investigate the combined effects of the Grashof number, Aspect ratio of the geometry, and Elliptical cylinder inclination angle on the dynamics of thermal and flow fields within the geometry investigated. COMSOL Multiphysics 5.5 version was used to resolve the non-dimensional transport equations, while simulations were performed to examine the implications of salient parameters such as the elliptical inclination angle , Grashof number and aspect ratio . The simulation outcomes are displayed as average Nusselt numbers, velocity streamlines, and isothermal contours. Findings from this study show that an increase in aspect ratio resulted in increased heat transfer at the elliptical cylinder wall, with the highest rate of heat transfer occurring when .0. Furthermore, the inclination angle increments when Gr= and led to a reduction in the average Nusselt number of the elliptical cylinder wall. At and AR ranges of , the value of the elliptical cylinder wall increased as the ellipse's inclination angle increased. The findings of this study have found use in heat transfer systems, particularly electronic cooling and nuclear technologies.

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Free-form and bionic spatial shells are popular in the area of spatial structures. Scallop-shaped surface is the product of evolution and a kind of spatial shells that can satisfy the mechanical requirements. Based on the scallop-shaped lattice shells, this paper focused on the optimization of geometric parameters. The principle of minimum strain energy was applied to conclude the influence law of the geometric parameters on mechanical properties. Finally the optimal values of geometric parameters were obtained. The results show that the optimization of geometric parameters presents the integrated significance to improve scallop-shaped lattice shells.

Abstract: Using the methods of dimensional analysis and the FLUENT analytic software, a quantitative description method is built; the influents of parameters, including the degree of curvature k=R/d, fluid density ρ, axial angle α, circle angle β, fluid outlet pressure P₀ and fluid velocity v on the distribution of pressure on inner surface of elbow pipe are studied from the simulation results; Finally, a three-dimensional distribution model of pressure which is considering the fluid characteristic and the elbow pipe geometric parameters is built by fitting the simulation data. The research conclusion lays the groundwork for strength check and structural design of the elbow pipe.

Abstract: This paper reports an effective design method for optimizing the geometric parameters of a micronozzle. Numerical analysis is conducted to predict the propulsion performance of micronozzles. By means of design of experiment (DOE), the number of numerical experiments is reduced dramatically from 1024 to 16. The interaction effects of the geometric parameters are taken into consideration for the first time. The results indicate that the interaction effects of geometric parameters cannot be neglected in choosing the optimal parameters for a practical design.

Abstract: The gas suction turnip seed metering device is the core requirement of precise seeding, in this article, through analysis and research of the geometric parameters of radish seeds, affect the seed is obtained by means of experiment draw the related factors of seed suction nozzle, including adsorption seed when the surrounding air velocity and adsorption under a certain air needed distance, and the specific parameters of these factors were determined.

Abstract: The effectiveness of heat transfer and the pressure drop coefficient of staggered elliptical tube banks are studied experimentally. The bank consists of 11 elliptical tubes of 0.75 equivalent diameter in an arrangement of 4-3-4. The major and the minor sub-axis of each tube are 24.70 mm and 12.35 mm respectively, and therefore the aspect ratio (AR) of the tube is 2.0. The geometric parameters of the bank are S_T = 24.70 mm, S_L = 37.00 mm and minimum frontal area B = 12.35 mm. Seven mid-tubes are internally heated by electrical heater of 69.6 Watt each. Experiment is conducted in a sub sonic wind tunnel and run with the wind velocities of 1 m/s 12.6 m/s which correspond with Reynolds number of = 346-6904. The results show that the effectiveness (ε) varied from 2144.44 to 15.26. It decreases exponentially at low Reynolds numbers and tended asymptotically at higher Reynolds number. The coefficient of pressure drop (CΔp) ranges from 7.21 to 4.41 decreases continuously at low Reynolds number and asymptotic at higher one.

Abstract: The finite element method is adopted to simulate the vibration control effectiveness of autobody thin-walled structure by using the piezoelectric patches. The geometric parameters of thickness and area are chosen as the influence factors to analyze the control effectiveness of piezoelectric vibration control system. The simulation results show that the base metal thickness, piezoelectric patch thickness and the area of piezoelectric patch are main parameters and influence the control effectiveness obviously. The influence rules of these geometric parameters are obtained.

Abstract: t is difficult to obtain high measurement accuracy in online detecting the thermal geometric parameters of hot large forgings, based on machine vision method. In this paper, firstly, a spectrum selective image acquisition method for high-temperature components is proposed, which can successfully reduced the effect of high temperature on image quality. Then, a measurement method based on the coding feature lines for geometric parameters of hot large forgings is employed, which can effectively improve the extraction efficiency of geometry characteristic information of high-temperature components. Experiments on the forging workshop show that measurement accuracy of diameters for cylindrical forging reaches 0.2% and the measurement time is 2.25 seconds; measurement accuracy of lengths for cuboid forging reaches 0.48% and the measurement time is 5.9 seconds. The experimental results have verified the feasibility and high efficiency of the proposed method for measuring the geometric parameters of hot large forgings.

Abstract: The diamond bird-beak XX-joint is a novel configuration for tubular structures and there are few correlated papers for it. Non-linear FE analyses are carried out on axially loaded XX-joints in order to study the mechanical properties of this type of joint. The individual influence of the following geometric parameters on the joint capacity, brace to chord width ratio β, chord width to wall thickness ratio 2γ, and brace to chord thickness ratio τ is made clear. Increasing either β or τ will increase the joint capacity and increasing 2γ will decreases joint capacity. The out-of-plane braces tension always decreases the ultimate capacity of joint and the equal tension and compression in the chord member have the same influence on the joint capacity. A reduction equation is proposed to consider the load effect of chord and out-of-plane braces axial forces.

Abstract: The national standards of the center distance, transmission ratio and transmission power of the planer enveloping toroidal worm are declared in abroad, but the geometric parameters and the main technology parameters is still calculated by the engineers according the design formula of the design handbook. At the same time, the non-standard parameters of the worm influence the standardization of the cutting tools especially the hob and add many difficulties and work load for the processing of the planer enveloping toroidal worm. The curvity modification theory and the optimization design software of the planer enveloping toroidal worm are introduced. The software is can not only optimize the relative parameters of the planer enveloping toroidal worm but also stimulate the engaged performance of the worm pair. Based on each kind of planer enveloping toroidal worm, the series of optimized parameters are calculated through the optimization design. The parameters which collect within national standards are the seriation and standardization parameters.