In order to solve the problem, which may be encountered by those former schemes, such as six accelerometer, nine accelerometer configuration, under specific conditions, a ten accelerometer configuration was pre...In order to solve the problem, which may be encountered by those former schemes, such as six accelerometer, nine accelerometer configuration, under specific conditions, a ten accelerometer configuration was presented to compute the rotational and translational accelerations of a rigid body, based on well known kinematics principles. The theoretical analysis shows that the configuration can meet the requirement. The simulation results of this scheme show promise for measuring a rigid body's rotational and translational accelerations.展开更多
This paper deals with the influence of phase modulated synthetic jet on the aerodynamics of the hump in a closed test section Of the Eiffel-type wind tunnel. Three experimental methods of measurement techniques of thi...This paper deals with the influence of phase modulated synthetic jet on the aerodynamics of the hump in a closed test section Of the Eiffel-type wind tunnel. Three experimental methods of measurement techniques of this phenomenon were used： the pressure profile using the Kiel total pressure probe, the velocity profile using the CTA （constant temperature anemometry） probe and the visualization of the flow field using the hot film and the thermo camera, The experimental results with and without the influence of the synthetic jet were compared, as well the impact of the phase shift of the neighbouring synthetic jets. As a reference case, the flow around the hump without the influence of the synthetic jet was selected. The results of the measurement are presented in figures and compared.展开更多
Astronaut's body mass is an essential factor of health monitoring in space.The latest mass measurement device for the International Space Station (ISS) has employed a linear acceleration method.The principle of th...Astronaut's body mass is an essential factor of health monitoring in space.The latest mass measurement device for the International Space Station (ISS) has employed a linear acceleration method.The principle of this method is that the device generates a constant pulling force,and the astronaut is accelerated on a parallelogram motion guide which rotates at a large radius to achieve a nearly linear trajectory.The acceleration is calculated by regression analysis of the displacement versus time trajectory and the body mass is calculated by using the formula m=F/a.However,in actual flight,the device is instable that the deviation between runs could be 6-7 kg.This paper considers the body non-rigidity as the major cause of error and instability and analyzes the effects of body non-rigidity from different aspects.Body non-rigidity makes the acceleration of the center of mass (C.M.) oscillate and fall behind the point where force is applied.Actual acceleration curves showed that the overall effect of body non-rigidity is an oscillation at about 7 Hz and a deviation of about 25%.To enhance body rigidity,better body restraints were introduced and a prototype based on linear acceleration method was built.Measurement experiment was carried out on ground on an air table.Three human subjects weighing 60-70 kg were measured.The average variance was 0.04 kg and the average measurement error was 0.4%.This study will provide reference for future development of China's own mass measurement device.展开更多
文摘In order to solve the problem, which may be encountered by those former schemes, such as six accelerometer, nine accelerometer configuration, under specific conditions, a ten accelerometer configuration was presented to compute the rotational and translational accelerations of a rigid body, based on well known kinematics principles. The theoretical analysis shows that the configuration can meet the requirement. The simulation results of this scheme show promise for measuring a rigid body's rotational and translational accelerations.
文摘This paper deals with the influence of phase modulated synthetic jet on the aerodynamics of the hump in a closed test section Of the Eiffel-type wind tunnel. Three experimental methods of measurement techniques of this phenomenon were used： the pressure profile using the Kiel total pressure probe, the velocity profile using the CTA （constant temperature anemometry） probe and the visualization of the flow field using the hot film and the thermo camera, The experimental results with and without the influence of the synthetic jet were compared, as well the impact of the phase shift of the neighbouring synthetic jets. As a reference case, the flow around the hump without the influence of the synthetic jet was selected. The results of the measurement are presented in figures and compared.
文摘Astronaut's body mass is an essential factor of health monitoring in space.The latest mass measurement device for the International Space Station (ISS) has employed a linear acceleration method.The principle of this method is that the device generates a constant pulling force,and the astronaut is accelerated on a parallelogram motion guide which rotates at a large radius to achieve a nearly linear trajectory.The acceleration is calculated by regression analysis of the displacement versus time trajectory and the body mass is calculated by using the formula m=F/a.However,in actual flight,the device is instable that the deviation between runs could be 6-7 kg.This paper considers the body non-rigidity as the major cause of error and instability and analyzes the effects of body non-rigidity from different aspects.Body non-rigidity makes the acceleration of the center of mass (C.M.) oscillate and fall behind the point where force is applied.Actual acceleration curves showed that the overall effect of body non-rigidity is an oscillation at about 7 Hz and a deviation of about 25%.To enhance body rigidity,better body restraints were introduced and a prototype based on linear acceleration method was built.Measurement experiment was carried out on ground on an air table.Three human subjects weighing 60-70 kg were measured.The average variance was 0.04 kg and the average measurement error was 0.4%.This study will provide reference for future development of China's own mass measurement device.
