To explore AC-DBD's ability in controlling dynamic stall,a practical SC-1095 airfoil of a helicopter was selected,and systematic wind tunnel experiments were carried out through direct aerodynamic measurements.The...To explore AC-DBD's ability in controlling dynamic stall,a practical SC-1095 airfoil of a helicopter was selected,and systematic wind tunnel experiments were carried out through direct aerodynamic measurements.The effectiveness of dynamic stall control under steady and unsteady actuation is verified.The influence of parameters such as constant actuation voltage,pulsed actuation voltage,pulsed actuation frequency and duty ratio on dynamic stall control effect is studied under the flow condition of k=0.15 above the airfoil,and the corresponding control mechanism is discussed.Steady actuation can effectively reduce the hysteresis loop area of dynamic lift,and control the peak drag and moment coefficient.For unsteady actuation,there is an optimal duty ratio DC=50%,which has the best effect in improving the lift and drag characteristics,and there is a threshold of pulsed actuation voltage in dynamic stall control.The optimal dimensionless frequency will not be found;different F+have different control advantages in different aerodynamic coefficients of different pitching stages.Unsteady actuation has obvious control advantages in improving the lift-drag characteristics and hysteresis,while steady actuation can better control the large nose-down moment.展开更多
Synergistic effects of pulsed DC dielectric barrier discharge （DBD） plasma and Indium modified HZSM-5 （In/HZSM-5） catalyst for C2H2 selective reduction of NOx at 200℃, in the presence of enriched oxygen by using ...Synergistic effects of pulsed DC dielectric barrier discharge （DBD） plasma and Indium modified HZSM-5 （In/HZSM-5） catalyst for C2H2 selective reduction of NOx at 200℃, in the presence of enriched oxygen by using a one-stage plasma-over-catalyst （POC） reactor, are reported. With a reactant gas mixture of 480 ppm NO, 500 ppm C2H2, 13.0% O2 in N2 and gas hourly space velocity （GHSV） = 10000 h^-1, pure catalytic, pure plasma-induced （discharges over fused silica pellets） and plasma-catalytic NOx conversion percentages are 45.0%, 4.0% and 92.2%, respectively. NOx conversion rates and energy costs were also compared for pulsed DC DBD and AC DBD reactors.展开更多
基金supported by the China Foundation Enhancement Fund(No.2019-077)National Natural Science Foundation of China(No.11802341)Research Project of Academician and Expert Workstation of the Green Aerotechnics Research Institute of Chongqing Jiaotong university(No.GATRI2020C06003)。
文摘To explore AC-DBD's ability in controlling dynamic stall,a practical SC-1095 airfoil of a helicopter was selected,and systematic wind tunnel experiments were carried out through direct aerodynamic measurements.The effectiveness of dynamic stall control under steady and unsteady actuation is verified.The influence of parameters such as constant actuation voltage,pulsed actuation voltage,pulsed actuation frequency and duty ratio on dynamic stall control effect is studied under the flow condition of k=0.15 above the airfoil,and the corresponding control mechanism is discussed.Steady actuation can effectively reduce the hysteresis loop area of dynamic lift,and control the peak drag and moment coefficient.For unsteady actuation,there is an optimal duty ratio DC=50%,which has the best effect in improving the lift and drag characteristics,and there is a threshold of pulsed actuation voltage in dynamic stall control.The optimal dimensionless frequency will not be found;different F+have different control advantages in different aerodynamic coefficients of different pitching stages.Unsteady actuation has obvious control advantages in improving the lift-drag characteristics and hysteresis,while steady actuation can better control the large nose-down moment.
基金National Natural Science Foundation of China(No.20077005)Natural Science Foundation of Dalian Nationalities University of China(No.20076205)
文摘Synergistic effects of pulsed DC dielectric barrier discharge （DBD） plasma and Indium modified HZSM-5 （In/HZSM-5） catalyst for C2H2 selective reduction of NOx at 200℃, in the presence of enriched oxygen by using a one-stage plasma-over-catalyst （POC） reactor, are reported. With a reactant gas mixture of 480 ppm NO, 500 ppm C2H2, 13.0% O2 in N2 and gas hourly space velocity （GHSV） = 10000 h^-1, pure catalytic, pure plasma-induced （discharges over fused silica pellets） and plasma-catalytic NOx conversion percentages are 45.0%, 4.0% and 92.2%, respectively. NOx conversion rates and energy costs were also compared for pulsed DC DBD and AC DBD reactors.
