A gas–solid coupling model involving coal seam deformation,gas diffusion and seepage,gas adsorption and desorption was built to study the gas transport rule under the effect of protective coal seam mining.The researc...A gas–solid coupling model involving coal seam deformation,gas diffusion and seepage,gas adsorption and desorption was built to study the gas transport rule under the effect of protective coal seam mining.The research results indicate:(1) The depressurization effect changes the stress state of an overlying coal seam and causes its permeability to increase,thus gas in the protected coal seam will be desorbed and transported under the effect of a gas pressure gradient,which will cause a decrease in gas pressure.(2) Gas pressure can be further decreased by setting out gas extraction boreholes in the overlying coal seam,which can effectively reduce the coal and gas outburst risk.The research is of important engineering significance for studying the gas transport rule in protected coal seam and providing important reference for controlling coal and gas outbursts in deep mining in China.展开更多
Pressure-sensitive paint(PSP)is a global pressure measurement technique.Compared with pressure transducers,PSP has significant advantages such as high spatial resolution and a lack of contact when applied to fast-rota...Pressure-sensitive paint(PSP)is a global pressure measurement technique.Compared with pressure transducers,PSP has significant advantages such as high spatial resolution and a lack of contact when applied to fast-rotating blades.However,due to the limitations of other pressure measurement techniques,the validation of PSP measurements on fast-rotating blades is generally difficult.In this work,a comprehensive study including PSP measurement,force balance measurement,and simulation was conducted on a 1 m-diameter propeller at the China Aerodynamic Research and Development Center.First,our computational fluid dynamics(CFD)code was validated by comparing the calculated aerodynamic thrust with the results from force balance measurements.Then,the pressure distributions on the propeller blade obtained by PSP were carefully compared with the CFD results under different working conditions.The results of PSP measurements,force balance measurements,and CFD showed good agreement,and the PSP measurement errors were estimated to be less than 5% of the dynamic pressure at the blade tip.Finally,the variations in pressure distribution under different rotating speeds and free-stream velocities were discussed.展开更多
基金supported by the National Natural Science Foundation of China (Nos.51304072,51574112 and 51404100)the Excellent Youth Foundation of Henan Scientific Committee (No.164100510013)+2 种基金the Key Scientific Research Project of Colleges and Universities of Henan Province (No.15A440010)the Chinese Ministry of Education Science and Technology Research Project (No.213022A)the Doctoral Foundation of Henan Polytechnic University (No.B2013-007)
文摘A gas–solid coupling model involving coal seam deformation,gas diffusion and seepage,gas adsorption and desorption was built to study the gas transport rule under the effect of protective coal seam mining.The research results indicate:(1) The depressurization effect changes the stress state of an overlying coal seam and causes its permeability to increase,thus gas in the protected coal seam will be desorbed and transported under the effect of a gas pressure gradient,which will cause a decrease in gas pressure.(2) Gas pressure can be further decreased by setting out gas extraction boreholes in the overlying coal seam,which can effectively reduce the coal and gas outburst risk.The research is of important engineering significance for studying the gas transport rule in protected coal seam and providing important reference for controlling coal and gas outbursts in deep mining in China.
基金supported by the Foundation of the State Key Laboratory of Aerodynamics(Grant No.SKLA2019040302)the National Natural Science Foundation of China(Grant No.11872038).
文摘Pressure-sensitive paint(PSP)is a global pressure measurement technique.Compared with pressure transducers,PSP has significant advantages such as high spatial resolution and a lack of contact when applied to fast-rotating blades.However,due to the limitations of other pressure measurement techniques,the validation of PSP measurements on fast-rotating blades is generally difficult.In this work,a comprehensive study including PSP measurement,force balance measurement,and simulation was conducted on a 1 m-diameter propeller at the China Aerodynamic Research and Development Center.First,our computational fluid dynamics(CFD)code was validated by comparing the calculated aerodynamic thrust with the results from force balance measurements.Then,the pressure distributions on the propeller blade obtained by PSP were carefully compared with the CFD results under different working conditions.The results of PSP measurements,force balance measurements,and CFD showed good agreement,and the PSP measurement errors were estimated to be less than 5% of the dynamic pressure at the blade tip.Finally,the variations in pressure distribution under different rotating speeds and free-stream velocities were discussed.
