The secondary coupling supporting technique on key parts (SCSTKP) is put forward. Based on the coupling state between supporting structure and surrounding rock of roadway, the key parts are divided into four types, an...The secondary coupling supporting technique on key parts (SCSTKP) is put forward. Based on the coupling state between supporting structure and surrounding rock of roadway, the key parts are divided into four types, and the characteristics of each type are described. The method to determine the optimum supporting time is also presented.展开更多
Temperature rise caused by windage power is a major limitation to the large-scale process of geotechnical centrifuges.However,there is no consensus on how to identify the key parts(parts with high windage power consum...Temperature rise caused by windage power is a major limitation to the large-scale process of geotechnical centrifuges.However,there is no consensus on how to identify the key parts(parts with high windage power consumption)and parameters(the velocity coefficientαand windage coefficient C_(i)),and the influence of idle power is often neglected in methods for calculating windage power.To address these issues,a Centrifugal Hypergravity and Interdisciplinary Experiment Facility(CHIEF)scaled model device was constructed,and the windage power was measured.Then,a computational fluid dynamics(CFD)model of the device was established and validated by experimental results.Simulation results were analyzed to quantify the proportion of the windage power in different parts of the device and summarize the variation law of key parameters.Finally,a novel windage power calculation equation was developed based on the elimination of the influence of the idle power.Results show that the role of the rotating arm cannot be ignored in the selection of key parts.The velocity coefficient and windage coefficient are a function of the device geometry and size,and are independent of the angular velocity.The windage power is proportional to the cube of the angular velocity after eliminating the effect of idle power.展开更多
文摘The secondary coupling supporting technique on key parts (SCSTKP) is put forward. Based on the coupling state between supporting structure and surrounding rock of roadway, the key parts are divided into four types, and the characteristics of each type are described. The method to determine the optimum supporting time is also presented.
基金supported by the National Major Science and Technology Infrastructure Project of China(No.2017-000052-73-01-002083)the Information Technology Center,Zhejiang University,China.
文摘Temperature rise caused by windage power is a major limitation to the large-scale process of geotechnical centrifuges.However,there is no consensus on how to identify the key parts(parts with high windage power consumption)and parameters(the velocity coefficientαand windage coefficient C_(i)),and the influence of idle power is often neglected in methods for calculating windage power.To address these issues,a Centrifugal Hypergravity and Interdisciplinary Experiment Facility(CHIEF)scaled model device was constructed,and the windage power was measured.Then,a computational fluid dynamics(CFD)model of the device was established and validated by experimental results.Simulation results were analyzed to quantify the proportion of the windage power in different parts of the device and summarize the variation law of key parameters.Finally,a novel windage power calculation equation was developed based on the elimination of the influence of the idle power.Results show that the role of the rotating arm cannot be ignored in the selection of key parts.The velocity coefficient and windage coefficient are a function of the device geometry and size,and are independent of the angular velocity.The windage power is proportional to the cube of the angular velocity after eliminating the effect of idle power.
