عنوان مقاله [English]
Moving sand and deposit them on existing tracks in the desert is one of the problems of traditional ballasted rail tracks. This problem resulted in Sand deposition on the railway lines and blocked, trains stopping, derailing, damaging to the structure and flexibility of the track and electrical signals and rolling stock. The thought of this research was to open the path of sand dunes using slab tracks hump , to do so we Analysis the effect of geometry hump in sand transport, optimize the previous plan form, determine the optimum distance of the rails and the floor slab and provide optimum design for sand easy movement with doing fluids essential analysis by software(using numerical model method) and on the basis of the least time that sand deposits on the slab in the direction and wind speed and set to obtain the optimum geometrical dimensions . In this context we have designed and simulated with the knowledge of mechanical fluids (aerodynamics), limits and requirements of designing and loading sleeper railway and also designed slabs, various geometrical shapes hump with the good aerodynamic behavior by using Rhaino software. These figures designed on the size, dimensions and height of the various modeling, such as circular model, minimized model, etc. and stimulated with the fluent simulation software. In this study ,the model parameters which used in assessment analyzing was included Vf (volume of fraction), Mass(sand weight ) and Q( flow of sand ) and V (volume of sand) that resulted in knowing a circular form conical shape with a height of 20 cm (M-C20) as one of the forms with better performance. It sended out the circular cross sections in the first stage of the sand entrance much faster than other forms of combination of normal oval (M-tnx) and minimumed elliptical (M-tmix) and based on the analysis done and study the diagrams, increasing the height of the hump does not necessarily increase the rate of sand passing that showed should be doubly careful in determining the height of the hump.