Hydrodynamic Simulation And Structural Optimization Of Channel-Controlled Integrated Equipment

Object: Intelligent decision-making and real-time regulation of quantitative aquatic products are important means and methods to achieve agricultural water-saving in irrigated areas.The quantity control integrated equipment based on the ultrasonic principle can provide technical support for the intelligent control of water volume control,high efficiency management,digital recording and water distribution.This paper focuses on the hydrodynamic simulation of the channel-controlled integrated equipment,the measurement lattice arrangement method,the field test and the structure optimization,and develops a mass-controlled integrated flow measurement method with high precision and suitable for the channel.Methods: In the study,Solidworks software and 3D printing technology was used to model and manufacture for the quantity control equipment.CFD software was used to calculate the internal flow field distribution of the quantity control equipment under different gate opening,different flow rates,different channel angles and different speeds.It reveals the internal flow state of the measuring section of the box with the opening of the gate,and establishs the structure and hydrodynamic simulation model.The significant differences in channel angle,opening and flow rate showed on the velocity correction coefficient were discussed,and the.the comprehensive velocity correction coefficient was obtained,the simplified flow rate calculation model of dot matrix measurement system applicable to different opening rates was obtained.The flow calculation formula established by numerical simulation was verified by actual measurement,and the reasonable installation angle range of sound channel was determined.On this basis,the shape and aspect ratio of the water inlet of the tank are optimized,and an optimized structural model with appropriate matching of the structure,aspect ratio and sound channel angle of the water inlet tank is put forward,which provides theoretical basis for the use of the product in irrigation area,the following conclusions are obtained.Results:(1)The flow calculation error between numerical simulation and actual measurement is 2.6%,and the simulation model can be used.Along the length direction of the box,under the same opening degree,with the increase of the length,the velocity area becomes more and more obvious,and there is a flat pattern distribution in the middle of the variation at both ends.Along the vertical direction of the box body,looking down from the top of the box,excepting for some abnormal points near the box,the speed shows an increasing trend,and the speed on the symmetry plane in the vertical direction is not completely symmetrical.Along the width direction of the box body.The closer the velocity distribution is to the ends of the wall of the box,the more obvious the difference,water flow encounters turbulence in buildings.From the plane where different sound channel installation angles are located,with the increase of the opening degree,the speed difference on the cross section decreases with the increase of the sound channel angle.The smaller the sound channel angle,the smaller the opening degree,and the greater the influence of the gate opening degree on the average flow speed on the cross section.At the same opening angle,the speed ratio ? first decreases with the increase of the channel angle,and finally approaches the same trend.From the distribution of streamline,From the streamline distribution,the small opening will produce reflow in the local area.When fully open,no recirculation zone will be generated,and the streamline distribution will be smooth and uniform.(2)The significant influences of channel angle,flow rate and opening degree on Speed correction factor K value are opening degree,channel angle and flow rate.The relationship between channel number and k value can be divided into two types.The first type: the value of k decreases with the increase of channel number,and k changes logarithmically with channel angle.The second type:the value of k decreases with the increase of channel number,then increases again,and k varies polynomial with channel angle.The installation angle of the sound channel is about 48°,and the K value changes stably.The K value shows a polynomial change trend with the change of the opening.Under different channel angles,the flow rate is not sensitive to the change of the flow rate,which indicates that the difference of the flow rate has little influence on the K value?Under the condition of different opening degrees,the K value varies greatly with the channel angle at the positions of channel 1-6,channel 7 and channel 8.(3)At the same flow rate,when the gate is fully opened,the flow velocity tends to increase with the increase of water level,but the increasing trend is slower and slower.Under the condition of the same sound channel angle,small opening,the flow rate increases with the increase of the upstream and downstream water level difference,and the flow rate shows a polynomial change trend with the change of the upstream and downstream water level difference.B opening,the flow rate does not change obviously with the water level difference.The measured average flow rate of the channel is the most consistent with the change of the number of channels.The flow error is the smallest,and the corresponding channel angle is about 48°.The connection between the front of the water inlet and the square box is a circular arc transition connection,which can be used as an optimization result of the transition section of the water inlet.The difference of the K value caused by the aspect ratio of the box and the angle of the channel can compensate each other.The aspect ratio is greater than or equal to 4.375.Conclusion:The basic structure and hydrodynamic model of the integrated equipment for channel volume control were built,and the distribution characteristics of the flow field inside the tank under the condition of the change of gate opening were revealed,speed correction factor was 1.056.The flow calculation formula for the equipment under different opening conditions was simplified,the channel installation angle was about 48°,and the flow error was the smallest.and the flow calculation model of the lattice system based on the ultrasonic principle was constructed.The flow calculation model was validated,and an optimized structural model with reasonable inlet structure,aspect ratio and channel angle matching were proposed.The curved connection was best with an aspect ratio of 4.375.