Study On The Airflow Characteristic About The Airfoil Induction Unit And Its Application Based On Coanda Effect

Ventilation is the main way of keeping indoor air quality and maintaining indoor thermal comfort.Fan and split air conditioner as the common ventilation installations are widely used in daily working and learning place,which play an important role in making a healthy indoor environment and improving working and studying efficiency.But available ventilation installations still have some problems unsolved.For example,the noise and the hidden danger caused by the fan blade shearing,fan blade cleaning difficultly,the uncomfortable draught rating brought by the jet distribution of the split air conditioner,and the cold sensation at indoor people's feet induced by warm air sinking hardly in winter.To overcome the problem mentioned above,Coanda effect is applied to the ventilation installation in this paper.The experimental and the numerical simulation about the airfoil inducing unit based on Coanda effect are carried out.Considering airfoil height and the distance between the adjacent airfoils,the change rules of the airflow characteristic and the induction rate are studied.On the basis of it,the ventilation installations put the airfoil inducing unit as the basic unit are simulated,and the flow characteristic of the airfoil inducing ventilation installations and the temperature distribution rule concerning the airfoil inducing air-conditioning unit in the room are explored.The detail research contents are as follows:(1)The single airfoil inducing unit model is built,and in order to explore the rule of the induction rate and the features about the streamflow distribution with the inducing velocity changing,the flow characteristic about the single airfoil inducing unit based on Coanda effect is simulated.The experimental device about the airfoil inducing unit was made,the flow pattern experimental and velocity tested at the tail of the airfoil inducing unit are carried out,the results of which verifies the numerical simulation results.(2)The physical models about two and infinite airfoil inducing units were made.Inducing velocity and the distance between adjacent airfoil inducing units having the impact on streamflow distribution,velocity distribution and induction rate were studied,which can lay a foundation for the study on the ventilation installation taking the airfoil inducing unit as the basic unit.(3)The ventilation installation physical models based on airfoil inducing unit with different frame sizes were built,the flow characteristic and the change rule of induction rate following different frame sizes and inducing velocity were analyzed.(4)The airfoil inducing indoor unit about air-conditioning was built,which has a comparison with traditional jet supply about air-conditioning,and the streamflow distribution and temperature distribution about the non-isothermal supply flow field in winter and summer condition were explored.