| Energy source shortage and environment deterioration have been the main crisis to our human been today, especially, the dramatic growth of vehicles accelerate the consumption of limited energy source and aggravate the pollution progress, therefore, optimizing the current vehicles to be more effective and environment-friendly is the top priority.Based on the principle of lubrication theory, this study proposed a novel method of utilizing soft porous material to accelerate the vehicles. The inspiration of this study comes from the mechanism of red cells gliding on the endothelial glycocalyx and snowboard sliding on the soft porous fresh snow, since there can generate huge lift force beneath the glycocalyx and snow when they are pressed. Comparing to the present maglev train, this strategy is more advantageous in saving energy and controlling carbon emissions. The porosity and high specific area make porous material a perfect candidate in the applications of tissue engineering, aerostatic bearings and noise absorption etc. The porous materials can exhibit unique performance in hydromechanics because of the existence of porosity, for the current applications, the pressure distribution and wave vibration in the porous bearing and noise absorption devices are significant factors to decide the effects, which are directly determined by the structure of the porous materials.This thesis validated the correctness of the novel thought by deriving and establishing the model of vehicles moving on the soft porous mat(SPM) from the N-S equation, and the modified Reynolds equation which fits the model is also obtained. Additionally, employing the Konzey-Carman equation under porous circumstance, the important parameters of porosity and permeability etc. have been introduced to describe the model more accurately. Through Matlab numerical simulations, the maximum of pressure distributing along x axis like parabola is obtained; Darcy permeability, porosity, radius of single fiber have been defined to be 5.O×10-9m2, 0.92,5μm, respectively; as the decrescence of the inclination angle, the velocity of the vehicle is approaching to the ultimate value, and the velocity will increase as the porosity increases while the angle keeps constant; while running on the SPM, the vehicle can reach to the ultimate velocity of about 720km/h which is far more than that of ordinary vehicles with the same energy consumption in very short time; the vehicle running on SPM can save about 80% of fuel consumption comparing to the ordinary one; the carbon emission curve of the model indicates that SPM can remarkably decrease the carbon emission to 1/6-1/3 of the ordinary amount.In the implementation, the SPM can be fabricated through a series of manufacturing processes including electrospinning or bubble electrospinning. The single synthesized fiber composing for SPM has diameter of 8μm-12μm, and the fibrous material has high porosity and specific area. Besides, the porous material exhibits unique performance in mechanical restoration after being compressed or impacted. In the short time compression test, it demonstrates that the restoration ratio of the material can reach to 99% when the compression ratio is less than 0.3; in the long time compression test, the restoration ratio can reach to 94% within 2 min's compression, and it decreases to 80% when the compression time is longer than 5 min. Hence the impressive characteristic of mechanical restoration of SPM ensures the performance of the air flow during the compression of the chassis of the vehicles.The SPM designed for this thesis have the height of 20cm, and they can be fixed on the base of high way or the tracks by splicing one by one together, the implementations have been given. Since the vehicles will float on SPM like maglev trains, the jet-propelled engine is proposed to substitute for the original one to ensure the driving force supply when the wheels are off land. The stability of the system is also considered such as the design in the turning for guaranteeing the safety. |
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