Optimal Design And Experimental Study Of Tangential Swirl Nozzle For Intelligent Toilet

As the most advanced cleaning product in the intelligent toilet,swirl nozzle has the advantages of wide cleaning area,high cleaning rate and comfortable cleaning,which can improve the enjoyment of toilet.However,the performance of the swirl nozzle is greatly affected by the structure size,and there are still some problems such as serious divergence of water flow,complex structure design and the inability to obtain stable small flow rotating water flow.In this paper,a tangential swirl nozzle for intelligent toilet is designed based on the generation mechanism of rotary jet and the theory of fluid mechanics.The effect of the structure parameters of the swirl nozzle on the performance of the nozzle was studied,and the influence law of the structure parameters of the swirl nozzle on the swirl characteristics of the internal and external flow field and the cleaning effect was clarified.The swirl nozzle is optimized based on response surface method,and the performance of the nozzle before and after optimization is compared.The specific work and results are as follows:1.The current research status of swirl nozzle in theory,experiment and application is summarized,and the relevant research methods of the swirl nozzle are systematically summarized.2.The performance test system for swirling nozzle was designed and built.For the first time,a rotation factor was defined to quantitatively represent the rotation strength of the water flow during the experiment.The results show that :(1)the rotary jet undulates obviously,which can form a rapidly rotating spiral flow and greatly increase the cleaning area.(2)compared with the non-rotating jet,the impact force performance of the rotary jet nozzle model is better,and the average impact force is improved by about 47%.The cleaning rate is stable at 83% in the 50 s,but it is still lower than the design requirements,so it still needs to be further optimized.3.The influence of swirl nozzle structure parameters on flow state,flow velocity and pressure in the internal and external flow field is analyzed by CFX calculation.The results show that :(1)the swirl flow improves the flow velocity in the internal and external flow field.(2)the tangential Angle of internal flow field velocity,jet pressure and the effect of swirl strength,internal flow state is affected,the entire process to the speed of change type ladder,general tangential velocity,radial velocity change presents the V shape,the axial inlet radius,cut to size has a great influence on both to swirl intensity change,and the internal flow field velocity,jet pressure and flow state in a smaller effect;(3)The strength of swirl in the swirl nozzle is larger than that in the outflow field under the same parameter.With the increase of the tangential inlet Angle,the strength of the swirling current in the internal and external fields increases gradually.With the increase of axial inlet radius,the variation trend of cyclone intensity in the internal and external field is the same,decreasing first,increasing and decreasing again.With the increase of the tangential inlet size,the strength of the swirling current in the internal and external field first increases,then decreases,then increases and then decreases,both of which show two maxima and one minimum.4.Imported by vortex nozzle tangential Angle,axial size and cut to size as independent variables,hitting force F,rotation factor δ and cleaning percentage S as response variables,based on the response surface method,the vortex nozzle structure parameters on the properties of nozzle coupling mechanism,the results show that:(1)the degree of single factor’s influence on the vortex nozzle cleaning percentage order:tangential inlet Angle,axial import radius,cut to size;The order of influence of single factor on the swirl nozzle’s rotation factor and striking force is: tangential inlet Angle,tangential dimension and axial inlet radius.(2)the optimal values of the structure parameters can be obtained by combining the optimal values of the swirl nozzle indexes: the tangential inlet Angle is between 65 ° and 66°,the tangential dimension is between 3.5mm×2.9mm and 3.5mm×3.1mm,and the axial inlet radius is between1.8mm and 2mm.5.The optimized nozzle structure: the tangential inlet Angle is 65°,the tangential dimension is 3.5mm×3mm,and the axial inlet radius is 1.9mm.The results showthat :(1)the rotation diameter of the rotating water flow expands,forming a spiral rotating water jet which is wound forward.(2)after optimization,the average impact force of the model nozzle is 0.122 n,which is about 51.6% higher than the initial design model.The cleaning performance is also significantly improved.After 50 years of nozzle flushing,the cleaning rate has reached 97%,which all meet the design requirements.