Papers by Keyword: Ellipsoid

Abstract: The ellipsoid is part of the family of rotation quadrics, along with the paraboloid and hyperboloid. This paper presents a study on the representation of the ellipsoid surface using various representation manners from descriptive geometry: the orthogonal projection on two planes of projection (the Monge projection), the axonometric projection and the projection with elevations. Every type of representation is exemplified by drawings.

Abstract: Drying can be defined as a simultaneous heat and mass transfer process between product and air drying. These phenomena have occurred due to thermal and moisture gradients and they are affected by different parameters. The inadequate management of this process can cause severe damage to the product such as cracking, loss of nutritional properties and even loss of the product quality. Thus, this paper proposes a numerical study of heat and mass transfer that occurs during the rough rice drying process, using the commercial software ANSYS CFX^®. Herein the grain was considered as ellipsoid of revolution.

Abstract: The large ellipsoidal aluminium plate system for missile in lab simulation[2], reaching a length of nearly 100 meters, is an important component of the laboratory. How to make it well-designed to avoid repetition and reduce the loss is the key to the project. This paper proposes the calculation methods andmodels for the geometrical parameters such as longitude and latitude line length, radius of curvature , keel curve direction on ellipsoid and deflecting ellipsoid. The practical problem is resolved successfully by designing the calculation models.

Abstract: Proceeding eigenvalue buckling analysis and geometric nonlinear analysis on schwedler single-layer ellipsoid reticulated shell with analysis software ANSYS, obtain structural buckling mode and ultimate bearing capacity at different short span and different rise-span ratio. Then analyze its impact on static stability of ellipsoid reticulated shell considering load asymmetric distribution and initial defect, conclude stability regular of schwedler single-layer ellipsoid reticulated shell. These study results can provide theoretical basis and technical reference for further studying on static stability of schwedler single-layer ellipsoid reticulated shell and engineering practice.

Abstract: Rough rice has high moisture content at harvest, and if their moisture content is not reduced to about 12% on the dry basis they decay due to infestation and mold growth. Drying process is generally performed by heating ambient air and then sending it by forced convection over the rough rice to be dried. The aim in heating air to a certain temperature is to reduce the relative humidity of the air, which has a positive effect on the drying potential. In this study, drying behavior of single layer rough rice for different drying air temperature was simulated by means of a liquid diffusion model numerically by finite element modeling and simulation software. The results show that temperature is an effective factor on the drying rate. The results also show that as drying proceeds, a moisture gradient develops within the grain. This slows down the drying rate considerably. Therefore, it can be concluded that performing drying with an intermittent period instead of continuous drying will cause a considerable energy-saving.

Abstract: A novel algorithm and experiment using phase retrieval to test aspheric mirror without auxiliary optical elements has been developed. To test aspheric mirror without auxiliary optical elements, a new algorithm has been invented to overcome the calculation difficulty due to the significant departure of aspheric surface from a sphere. In this algorithm, the aspheric surface is fitted into several annular ellipse sub-apertures, and each sub-aperture aberration can be retrieved the same as ball mirror testing. The whole aspheric surface can be retrieved by stitching all the subapertures together. An experiment has been carried out to test the validity of this algorithm.