Optimization Design Of Structural Parameters Of Large Flow Low Pressure Drop Self-excited Pulse Nozzle

The pulse jet modulated by the self-excited pulse jet nozzle has good impact characteristics compared to the continuous jet.A new turbo torsional impact drilling tool with nozzle short section above the drill bit can provide periodic torsional impact to the drill bit,slow down the stick-slip vibration of the lower drill bit and improve drilling efficiency.In this paper,the numerical simulation test method is used to optimize the structural parameters of the large flow low pressure drop self-excited pulse nozzle.The nozzle pressure drop,flow pulse amplitude and frequency parameters are used to characterize the nozzle pulse effect.The linear programming model is used to establish the optimal criteria.The optimal nozzle structure is obtained quantitatively.And the fluid parameters are analyzed.According to different borehole sizes the three-dimensional structure of large-flow low-pressure drop self-excited pulse nozzles with different sizes is designed.At the same time,the Fluent fluid dynamics simulation software is used to analyze the variation law of the airbag in the three-dimensional structure gas volume fraction cloud image.And the impact force of the nozzle jet pulse jet is tested.The results showed that it has good effect.Based on the optimal nozzle structure,this paper redesigns a new turbo torsional impact drilling tool assembly drawing to provide an optimization idea for further improving the torsional impact effect and improving drilling efficiency.