A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid ...A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid dynamics.The effects of the applied voltage on the distribution of velocity and temperature in initially static air are parainetrically studied.Furthermore,the spatial structure of plasma discharge and the resulting force contours in streamwise and normal directions are discussed in detail.The result shows that the plasma actuator produces a net force that should always be directed away from the exposed electrode,which results in an ionic wind pushing particles into a jet downstream of the actuator.When the energy added by the plasma is taken into account,the ambient air temperature is increased slightly around the electrode,but the velocity is almost not affected.Therefore it is unlikely that the induced flow is buoyancy driven.For the operating voltages considered in this paper,the maximum induced velocity is found to follow a power law,i.e.,it is proportional to the applied voltage to the 3.5 power.This promises an efficient application in the flow control with plasma actuators.展开更多
The charge transfer potential barrier （CTPB） formed beneath the transfer gate causes a noticeable image lag issue in pinned photodiode （PPD） CMOS image sensors （CIS）, and is difficult to measure straightforwardl...The charge transfer potential barrier （CTPB） formed beneath the transfer gate causes a noticeable image lag issue in pinned photodiode （PPD） CMOS image sensors （CIS）, and is difficult to measure straightforwardly since it is embedded inside the device. From an understanding of the CTPB formation mechanism, we report on an alternative method to feasibly measure the CTPB height by performing a linear extrapolation coupled with a horizontal left-shift on the sensor photoresponse curve under the steady-state illumination. The theoretical study was pertbrmed in detail on the principle of the proposed method. Application of the measurements oil a prototype PPD-CIS chip with an array of 160 ×160 pixels is demonstrated. Such a method intends to shine new light oil the guidance for the lag-free and high-speed sensors optimization based on PPD devices.展开更多
基金supported by the Foundation for Innovative Research Groups of National Natural Science Foundation of China(No.51121004)National Natural Science Foundation of China(No.50976026)
文摘A numerical investigation is conducted to explore the evolution of a plasma discharge and its interaction with the fluid flow based on a self-consistent fluid model which couples the discharge dynamics with the fluid dynamics.The effects of the applied voltage on the distribution of velocity and temperature in initially static air are parainetrically studied.Furthermore,the spatial structure of plasma discharge and the resulting force contours in streamwise and normal directions are discussed in detail.The result shows that the plasma actuator produces a net force that should always be directed away from the exposed electrode,which results in an ionic wind pushing particles into a jet downstream of the actuator.When the energy added by the plasma is taken into account,the ambient air temperature is increased slightly around the electrode,but the velocity is almost not affected.Therefore it is unlikely that the induced flow is buoyancy driven.For the operating voltages considered in this paper,the maximum induced velocity is found to follow a power law,i.e.,it is proportional to the applied voltage to the 3.5 power.This promises an efficient application in the flow control with plasma actuators.
基金Project supported by the National Defense Pre-Research Foundation of China(No.51311050301095)
文摘The charge transfer potential barrier （CTPB） formed beneath the transfer gate causes a noticeable image lag issue in pinned photodiode （PPD） CMOS image sensors （CIS）, and is difficult to measure straightforwardly since it is embedded inside the device. From an understanding of the CTPB formation mechanism, we report on an alternative method to feasibly measure the CTPB height by performing a linear extrapolation coupled with a horizontal left-shift on the sensor photoresponse curve under the steady-state illumination. The theoretical study was pertbrmed in detail on the principle of the proposed method. Application of the measurements oil a prototype PPD-CIS chip with an array of 160 ×160 pixels is demonstrated. Such a method intends to shine new light oil the guidance for the lag-free and high-speed sensors optimization based on PPD devices.
