Study On The Air Flow Characteristics Of Vortex Outlet

People spend more than 80% of their time indoors.A good indoor thermal environment can not only improve people’s quality of life,but also improve work efficiency.There are many factors affecting indoor thermal comfort,such as temperature,relative humidity,turbulence and airflow characteristics.In the past,more emphasis was put on the negative effects of air blowing sensation on the thermal comfort of air-conditioned rooms,especially the negative effects of speed and turbulence.However,these were later proved not to be in line with the thermal sensation of people in hot areas.In ASHRAE,it was first proposed that air flow can improve the thermal comfort in hot environment.It is generally accepted that natural ventilation with windows is used to improve indoor air quality.The changeable,comfortable and soft characteristics of natural wind are mainly due to its airflow characteristics.The airflow characteristics of natural wind belong to turbulent motion,which is composed of vortices of different scales.However,natural ventilation with windows is often restricted by outdoor climate conditions and building structure conditions.In order to create a dynamic air-conditioned indoor thermal environment,many scholars have put into the research of imitating natural wind.Among them,it is a good way to improve the terminal air supply mode of air conditioning.In this paper,based on the wake flow characteristics of the wing,the wing is used in the innovative design of the air conditioning terminal,and a new vortex air supply outlet is designed.When the air is sent out through the air supply outlet,the air pulsation occurs,which brings the necessary micro stimulation to the human body and improves the thermal comfort of the human body.In this paper,CFD numerical simulation technology is used to study the air flow characteristics of the vortex air supply outlet,the parameters of the wing deflector which affect the air flow characteristics of the vortex air supply outlet,and the influence of the air supply outlet on the indoor flow field and temperature field.The first chapter is the introduction,which mainly describes the current research status of the influence of indoor air flow characteristics on human thermal comfort,the research status of air flow characteristics at air outlet,the air flow characteristics of natural wind and wing wake.The detached vortex street(Carmen vortex street)is an important part of the wing wake,which is composed of many vortices of different scales.The essence of this vortex street is turbulent motion,which has both randomness and orderliness.In the second chapter,the governing equations,turbulence models and numerical methods for solving the equations are explained.The flow in this paper belongs to isothermal / non isothermal steady low-speed incompressible turbulent flow.The N-S equation is used as the governing equation,the standard k-two equation model is used as the turbulence model,and the simple method is used as the discretization method.At the same time,the grid independence is verified.In the third chapter,the CFD numerical simulation method is used to study the flow characteristics of vortex outlet in infinite space.At the same time,the air flow characteristics of vortex air supply outlet,louver air supply outlet and non deflector air supply outlet in infinite space are compared and analyzed.In the fourth chapter,using CFD numerical simulation method,the structural parameters of wing deflector with vortex outlet in infinite space are systematically studied,and the air velocity,vorticity and downstream air flow characteristics of the outlet are analyzed,so as to determine the main structural parameters of wing deflector,including airfoil,chord length and installation angle.In the fifth chapter,CFD numerical simulation method is used to study the influence of vortex outlet on the flow field and temperature field of indoor working area.This paper mainly analyzes the influence of the vortex outlet on the flow field and temperature field in the vertical and horizontal directions of the indoor working area.At the same time,the effects of vortex air supply outlet,louver air supply outlet and non deflector air supply outlet on the indoor flow field and temperature field distribution were compared and analyzed.