The elimination of transverse wavevectors during the propagation of electromagnetic waves is highly desirable because this would have a wide range of applications in probing,imaging,and communication.In this research,...The elimination of transverse wavevectors during the propagation of electromagnetic waves is highly desirable because this would have a wide range of applications in probing,imaging,and communication.In this research,we propose and experimentally demonstrate a simple method to suppress transverse wavevectors by using coherent wave combinations.Using theoretical analysis and numerical simulation,we show that transverse wavevectors can be greatly suppressed during propagation.For further verification,we perform experiments with light waves to realize coherently combined beams;our experimental results are in good agreement with the simulated results.More importantly,we generate pin-like optical beams using this method,and pin-like optical beams exhibit superior propagation behavior over conventional Gaussian beams in turbulent fluids.展开更多
A flow control system that combined steady Vortex Generator Jets and Deflected Trailing-edge(VGJs-DT) to decrease the low pressure turbine(LPT) blade numbers was presented.The effects of VGJs-DT on energy loss and flo...A flow control system that combined steady Vortex Generator Jets and Deflected Trailing-edge(VGJs-DT) to decrease the low pressure turbine(LPT) blade numbers was presented.The effects of VGJs-DT on energy loss and flow of low solidity low pressure turbine(LSLPT) cascades were studied.VGJs-DT was found to decrease the energy loss of LSLPT cascade and increase the flow turning angle.VGJs-DT decreased the solidity by 12.5%without a significant increase in energy loss.VGJs-DT was more effective than steady VGJs.VGJs-DT decreased the energy loss and increased the flow angle of the LSLPT cascade with steady VGJs.VGJs-DT can use 50%less mass flow than steady VGJs to inhibit the flow separation in the LSLPT cascade.The deflected trailing edge enhanced the ability of steady VGJs to resist flow separation.Overall,VGJs-DT can be used to control flow separation in LPT cascade and reduce the blade numbers of low pressure turbine stage.展开更多
文摘The elimination of transverse wavevectors during the propagation of electromagnetic waves is highly desirable because this would have a wide range of applications in probing,imaging,and communication.In this research,we propose and experimentally demonstrate a simple method to suppress transverse wavevectors by using coherent wave combinations.Using theoretical analysis and numerical simulation,we show that transverse wavevectors can be greatly suppressed during propagation.For further verification,we perform experiments with light waves to realize coherently combined beams;our experimental results are in good agreement with the simulated results.More importantly,we generate pin-like optical beams using this method,and pin-like optical beams exhibit superior propagation behavior over conventional Gaussian beams in turbulent fluids.
基金supported by the National Foundation for Innovative Research Groups of China(Grant No.51421063)
文摘A flow control system that combined steady Vortex Generator Jets and Deflected Trailing-edge(VGJs-DT) to decrease the low pressure turbine(LPT) blade numbers was presented.The effects of VGJs-DT on energy loss and flow of low solidity low pressure turbine(LSLPT) cascades were studied.VGJs-DT was found to decrease the energy loss of LSLPT cascade and increase the flow turning angle.VGJs-DT decreased the solidity by 12.5%without a significant increase in energy loss.VGJs-DT was more effective than steady VGJs.VGJs-DT decreased the energy loss and increased the flow angle of the LSLPT cascade with steady VGJs.VGJs-DT can use 50%less mass flow than steady VGJs to inhibit the flow separation in the LSLPT cascade.The deflected trailing edge enhanced the ability of steady VGJs to resist flow separation.Overall,VGJs-DT can be used to control flow separation in LPT cascade and reduce the blade numbers of low pressure turbine stage.
