Aerodynamic Shape Design And Optimization Of Dandelion Like Aircraft

In the design of aircraft,many creatures in nature provide ready-made learning materials for people.For example,in terms of form,simple and beautiful biological modeling provides multi-directional choices for aircraft design.In terms of function,diverse and complex biological structures provide a scientific basis for its technology.Bionics is the trend of aircraft design in the future,which can solve many practical problems.Based on the requirements of high efficiency and energy saving of aircraft in flight and the high efficiency flight mode of dandelion seeds,this paper designs a dandelion like vehicle with the same flight characteristics by studying the flight characteristics of dandelion seeds.First of all,the research work and progress of dandelion seed flight characteristics at home and abroad were discussed from three aspects of theoretical research,simulation research and experimental research,and the development and current situation of dandelion seed flight characteristics were analyzed.Secondly,through the study of dandelion seed dispersal mechanism,biological characteristics and the main factors affecting dandelion seed flight,the simplified model of dandelion seed was established,and the mechanical analysis of dandelion seed was carried out according to the relevant theories of fluid mechanics.The biological characteristics of dandelion flight were obtained,which provided theoretical support for the subsequent design of dandelion like aircraft.Then,according to the simplified model of dandelion seeds,different geometric models of dandelion seeds were established.The accuracy of the simulation is verified by the comparison between the numerical simulation results and the experimental results.Based on the numerical analysis of dandelion seed model with different number,shape,central disc size and porosity disc,the effects of different structure of dandelion seed on the flight characteristics of dandelion seed were studied,and the optimal size of dandelion seed model structure was determined.According to the results of numerical analysis,the main and secondary factors affecting the seed flight of Taraxacum mongolicum were determined by orthogonal test.Then,according to the research on the flight characteristics of dandelion seeds,the dandelion like aircraft with different flight characteristics was designed.Based on the research of drag coefficient and vortex of different dandelion like aircrafts,the aerodynamic shape optimization design of dandelion like aircrafts is carried out.Finally,a test platform is built to test the throwing of the dandelion like aircraft.According to the test data,the landing trajectory and attitude of the dandelion like aircraft are analyzed,and the landing speed and drag coefficient of the dandelion like aircraft are calculated.At the same time,the flight characteristics of the designed dandelion like aircraft are verified.