The 〈 110 〉 -oriented TTb0.3Dy0.7Fe1.95 polycrystalline alloy was magnetically annealed, and its influence on jump effect of magnetostriction was investigated. In the vacuum superconductive high magnetic field equip...The 〈 110 〉 -oriented TTb0.3Dy0.7Fe1.95 polycrystalline alloy was magnetically annealed, and its influence on jump effect of magnetostriction was investigated. In the vacuum superconductive high magnetic field equipment, 〈 110 〉 -oriented Tb0.3Dy0.7Fe1.95 polycrystalline alloy of the directional solidification was annealed at 623 and 723 K for 5 min under the magnetic field vertical to specimen axis. It is found that magnetic annealing can enhance the jump effect under compressive stress, and increase the saturated magnetostriction coefficient λs, the λs of the magnetic annealing specimens at 623 K under 8.1 MPa is attained to 1950 × 10^-6, Magnetic annealing increases the maximum of dynamic magnetostriction coefficient, d33^max, as well as the magnetic field for d33^max under 8.1 MPa.展开更多
A nonlinear and time-varying gyroplane jump takeoff dynamics model considering the unsteady ground effect and the rapid blade-pitch increase(RBPI) is developed and validated against the experiment data.The precisions ...A nonlinear and time-varying gyroplane jump takeoff dynamics model considering the unsteady ground effect and the rapid blade-pitch increase(RBPI) is developed and validated against the experiment data.The precisions of the proposed model,an experienced Hollmann model and three other simplified models are compared by displaying the height and rpm time histories of those models and the experimental data.The mean square errors(MSE) of the height histories and maximum height errors(MHE) between those models are calculated and given out.The statistics provide a kind of evaluation method of importance of the unsteady ground effect,RBPI,and the induced velocity on jump takeoff performance in vertical phase.The impact of the unsteady ground effect and RBPI on the thrust and induced velocity of the experimental rotor of a small scale platform is analyzed.The study indicates that the proposed model agrees better with the experimental data than other models.It is useful for predicting the gyroplane jump takeoff performance for design.展开更多
文摘The 〈 110 〉 -oriented TTb0.3Dy0.7Fe1.95 polycrystalline alloy was magnetically annealed, and its influence on jump effect of magnetostriction was investigated. In the vacuum superconductive high magnetic field equipment, 〈 110 〉 -oriented Tb0.3Dy0.7Fe1.95 polycrystalline alloy of the directional solidification was annealed at 623 and 723 K for 5 min under the magnetic field vertical to specimen axis. It is found that magnetic annealing can enhance the jump effect under compressive stress, and increase the saturated magnetostriction coefficient λs, the λs of the magnetic annealing specimens at 623 K under 8.1 MPa is attained to 1950 × 10^-6, Magnetic annealing increases the maximum of dynamic magnetostriction coefficient, d33^max, as well as the magnetic field for d33^max under 8.1 MPa.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51505031)
文摘A nonlinear and time-varying gyroplane jump takeoff dynamics model considering the unsteady ground effect and the rapid blade-pitch increase(RBPI) is developed and validated against the experiment data.The precisions of the proposed model,an experienced Hollmann model and three other simplified models are compared by displaying the height and rpm time histories of those models and the experimental data.The mean square errors(MSE) of the height histories and maximum height errors(MHE) between those models are calculated and given out.The statistics provide a kind of evaluation method of importance of the unsteady ground effect,RBPI,and the induced velocity on jump takeoff performance in vertical phase.The impact of the unsteady ground effect and RBPI on the thrust and induced velocity of the experimental rotor of a small scale platform is analyzed.The study indicates that the proposed model agrees better with the experimental data than other models.It is useful for predicting the gyroplane jump takeoff performance for design.
