Research On The Influence Of Bionic Air Conditioner Blades On The Thermal Environment And Sound Field In The Car

With the improvement of the national economy and the development of the automobile industry,the functions of automobiles tend to be diversified.While consumers are pursuing basic functions of automobiles,they also pay more and more attention to the comfort of riding.The ride comfort of a car is not only related to the ride comfort of the car,but also related to the noise and vibration in the car and the distribution of airflow in the car.Due to the complex interior space of the car and the relatively closed environment,if the noise inside the car is too loud and the air distribution is uneven,the driver's long-term stay in the space will cause problems such as irritability and divergence of attention,which may easily cause traffic accidents and threaten people.Safety of life and property.Therefore,the research on the influence of the thermal environment and sound field in the car cabin is of great significance.Existing research on the thermal environment in the cab mainly focuses on the layout of air-conditioning air outlets,the layout of air-conditioning grilles,the impact of air supply temperature and air speed on the thermal environment in the cab,and the impact of airconditioning pipelines on the noise distribution in the cab The research on the influence of the shape of the grille blades of the air-conditioning air outlet on the airflow organization and noise value in the cab is not paid much attention.In this paper,inspired by the excellent aerodynamic characteristics of the dragonfly wing folds,the air-conditioning air outlet grille blades are bionic optimization.Numerical simulation is performed on cabs with different shapes of bionic blades,and the optimal bionic blades are selected by analyzing the air distribution and noise value in the cab.First,a single combined bionic blade is analyzed in a steady state,and a blade model with a lower resistance value is selected,and the blade model is deformed in a specific way to obtain a variety of fold-shaped blades.In this paper,a single blade is extracted for numerical simulation,and the simulation results are compared with the experimental results.It can be seen from the calculation that the time-averaged velocity error obtained by the experiment and the simulated time-averaged velocity error is less than 3.8%,which verifies the reliability of the simulation results.The bionic blades in this paper mainly include pleated blades distributed along the flow direction and pleated blades distributed laterally.First,the model is used to simulate the steady state and transient state of the cab,and the flow field,temperature field and the temperature field in the cab under the four working conditions are obtained,and the flow field,temperature field and temperature field in the cab with different blades are compared.Blade drag coefficient and other results,and then use the large eddy simulation calculation method combined with the FW-H acoustic analog equation to analyze the influence of the blade shape difference on the noise value in the cab,and select the better blades from the transversely distributed corrugated blades(2-p4 type),a better blade(1-p5 type)is selected from the pleated blades distributed in the flow direction.Finally,considering the effect of blade shape on the thermal environment and noise value in the cab,the optimal blade(2-p4 type)is selected.The simulation results show that the drag coefficient of the pleated blades distributed along the flow direction gradually decreases with the increase of the number of folds.Compared with the flat blades,the blades of this structure have a more obvious influence on the noise level in the cab,but except for the 1-p5 type blades,other blades have no significant impact on the thermal environment in the cab;the corrugated blades distributed along the transverse direction have a significant drag reduction effect and an impact on the noise value compared to flat blades.Among them,2-p4 type blades have excellent effects on the noise value and thermal environment in the cab.In summary,the two fold shaped blades of dragonfly wings have good effects on the flow field,temperature field and noise value in the cab.However,the comparison of 2-p4 type blades and 1-p5 type blades,2-p4 type blade has better effect.