High-pressure pulsed waterjet technology has considerable development potential in the field of rock fragmenta-tion.To overcome the shortcomings of existing pulsed jets,a self-supercharging pulsed waterjet(SSPWJ)generation method is proposed,which is based on the theory of the pulsed waterjet and the principle of hydraulic boosting.The proposed method changes the flow direction of the fluid medium through the valve core to make the piston recip-rocate in the cylinder and relies on the effective area difference between the front and rear chambers in the stroke stage of the piston to realize the organic combination of"pulse"and"supercharging"of the jet,thus forming an SSPWJ.On the basis of the formation principle of the SSPWJ,a SSPWJ testing platform was constructed,and tests were performed on the jet pressure acquisition,morphology capture,and granite erosion.Both the jet pressure and the jet morphology exhibited periodic changes,and a higher pulse pressure was obtained at lower inlet pressure.The error of the pressure ratio calculated according to the experimental results was＜3％relative to the theoretical design value,confirming the feasibility of the method.The pulse pressure and pulse frequency are controllable;that is,as the inlet flow rate increases in the stroke stage of the piston,the pulse pressure and pulse frequency increase,and the pulse duration decreases.As the inlet flow rate increases in the backward-stroke stage of the piston,the pulse frequency increases,and the pulse pressure and pulse duration remain unchanged.Under the combined action of the water-hammer pressure,high-speed lateral flow,and high-frequency dynamic load of the SSPWJ,local flaky exfoliation was observed when the granite surface was eroded.The results of this study lay the foundation for enriching the theory of pulsed jet generation and expanding its application range.

Zhaolong Ge;Yuanfei Ling;Jiren Tang;Yiyu Lu;Yangkai Zhang;Lei Wang;Qi Yao

State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400030,China;National&Local Joint Engineering Laboratory of Gas Drainage in Complex Coal Seam,Chongqing University,Chongqing 400030,China;College of Source and Safety,Chongqing University,Chongqing 400030,China

中国机械工程学报

[1]Zhaolong Ge;Yuanfei Ling;Jiren Tang;Yiyu Lu;Yangkai Zhang;Lei Wang;Qi Yao-.Formation Principle and Characteristics of Self-Supercharging Pulsed Water Jet)[J].中国机械工程学报,2022(03):250-263

Supercharging,supercharging,SSPWJ,rocate

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