In order to investigate the mechanism of the temperature oscillation in loop heat pipes,this paper investigated the movement of the phase interface as the changed input power by a mass-spring-damper model.The model wa...In order to investigate the mechanism of the temperature oscillation in loop heat pipes,this paper investigated the movement of the phase interface as the changed input power by a mass-spring-damper model.The model was solved with MATLAB and was used to explain the high-frequency and low-amplitude temperature oscillation.Temperature variation with the input power from 20 W to 75 W was investigated based on a LHP prototype in a literature.The model agreed well with the experimental data in the literature.The simulation results suggested that the movement of the liquid column was caused by the fluctuation of pressure difference applied on the liquid column and the stiffness coefficients of the vapor springs increasing with the input power.According to parameter analyses,the temperature oscillation at the outlet of the condenser can be weakened by increasing the mass of the liquid column and keeping the temperature at the outlet of the condenser steady.展开更多
It can be beneficial to reduce vibrations in shipboard piping, so the authors designed a new kind of piping damper with a plunger-type accumulator.Special requirements for the piping damper included low impact displac...It can be beneficial to reduce vibrations in shipboard piping, so the authors designed a new kind of piping damper with a plunger-type accumulator.Special requirements for the piping damper included low impact displacement, low speed, as well as an appropriate locking speed.Inside the damper, a plunger-type accumulator was installed and on the outside of the piston rod, a tube with exposed corrugations was added.Between the piston and the cylinder, a clearance seal was added.Using mathematical modeling, the effects of the dynamic performance of the damper's impact displacement on vibrations were observed.Changes to the clearance between the piston and the cylinder, the stiffness of the spring in the accumulator, the throttle valve size, and locking speed resistance of the damper were respectively simulated and studied.Based on the results of the simulation, dampers with optimal parameters were developed and tested with different accumulator spring stiffnesses and different throttles.The simulation and experimental results showed that parameters such as seal clearance between piston and cylinder, accumulator spring stiffness and throttle parameters have significant effects on the damper's impact displacement, low speed resistance and locking speed.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51276012)
文摘In order to investigate the mechanism of the temperature oscillation in loop heat pipes,this paper investigated the movement of the phase interface as the changed input power by a mass-spring-damper model.The model was solved with MATLAB and was used to explain the high-frequency and low-amplitude temperature oscillation.Temperature variation with the input power from 20 W to 75 W was investigated based on a LHP prototype in a literature.The model agreed well with the experimental data in the literature.The simulation results suggested that the movement of the liquid column was caused by the fluctuation of pressure difference applied on the liquid column and the stiffness coefficients of the vapor springs increasing with the input power.According to parameter analyses,the temperature oscillation at the outlet of the condenser can be weakened by increasing the mass of the liquid column and keeping the temperature at the outlet of the condenser steady.
基金Supported by the National Natural Science Foundation of China under Grant No.10972086
文摘It can be beneficial to reduce vibrations in shipboard piping, so the authors designed a new kind of piping damper with a plunger-type accumulator.Special requirements for the piping damper included low impact displacement, low speed, as well as an appropriate locking speed.Inside the damper, a plunger-type accumulator was installed and on the outside of the piston rod, a tube with exposed corrugations was added.Between the piston and the cylinder, a clearance seal was added.Using mathematical modeling, the effects of the dynamic performance of the damper's impact displacement on vibrations were observed.Changes to the clearance between the piston and the cylinder, the stiffness of the spring in the accumulator, the throttle valve size, and locking speed resistance of the damper were respectively simulated and studied.Based on the results of the simulation, dampers with optimal parameters were developed and tested with different accumulator spring stiffnesses and different throttles.The simulation and experimental results showed that parameters such as seal clearance between piston and cylinder, accumulator spring stiffness and throttle parameters have significant effects on the damper's impact displacement, low speed resistance and locking speed.
