The vibration attenuation mechanism was expounded. The influence of different damping layer shear modulus and magnetic stiffness on the loss factor of beam for the first mode by MCLD treatment was evaluated.

3) the three support structure of the shaft system made coupling between the first mode of the exciter rotor and the second mode of the generator rotor.

The result in this paper about the first mode of stability and the numerical transition prediction about plate fit the result of experiments very well.

It gives also a stability analysis on the first mode of the boundary layer of flat plane and a forecasting of transition point. Results are discussed and compared with observations.

Then the variation of the first mode is adopted as the damage signature, the sensitivity and the independent of normalization are certificated, and the advantage of which is listed.

Ice induced displacement responses of offshore fixed platforms are investigated in both time domain and frequency domain. The relationships of ice induced displacement responses with ice characteristics,ice directions and structural types of platforms are analyzed and determined. And an important conclusion is obtained for the first time that ice breaking frequency and the natural frequency of the first mode of the platform are the two main factors which dominate the amplitude of vibration.

The method of multiple scales combined with the Cartesian transformation is used solve to the nonlinear differential equations and derive a set of nonlinear modulation equations for the principal parametric resonance of the first mode and 3:1 internal resonance between the first two modes. Then, the modulation equations are numerically solved to obtain the steady-state response and the stability assessment of the beam.

Since the subharmonic resonance curve of the first mode and the combination resonance curve extend as far as the region of the second mode resonance, there are some parameter regions in which several motions may occur corresponding to the same frequency of the pulsating flow.

The natural frequency,quality factor,first mode of fold beam and Young's modulus of the double linear vibratory gyroscope were measured by the new setup.

It has been shown that the middle regime is unstable, only the first mode of the small disturbances being unstable over a broad range of the parameters.

In the first mode, which is realized at rather substantial differences between the initial temperature of the reservoir and the temperature of water being injected, the condensation of steam occurs at the interface.

In the first mode, input processes are digitized after a START signal; in the second mode, a signal exceeding a preset threshold is uninterruptedly sought for and recorded.

These velocity deviations have been determined for the first mode of Love waves and for the zero mode of SH waves as functions of the thickness and acoustic properties of the coating and substrate.

It is shown that the frequency band of the received signal can be broadened by introducing a frequency-time correction of the propagation time of the first mode as a function of the sound frequency.

A mathematical model is established by means of the finite element transfer matrix method in order to calculate the dynamic response of a multispan, multi bearing 300MW turbo genarator set′s rotor system. The transient response of the gencrator exciter rotor and the bearing seal system is calculated. The dynamic characteristic of the seal ring and its effect on rotor vibration are analyzed and computed. A site of tests indicated three main reasons for over limit vibration in the positions near the bearing:...

A mathematical model is established by means of the finite element transfer matrix method in order to calculate the dynamic response of a multispan, multi bearing 300MW turbo genarator set′s rotor system. The transient response of the gencrator exciter rotor and the bearing seal system is calculated. The dynamic characteristic of the seal ring and its effect on rotor vibration are analyzed and computed. A site of tests indicated three main reasons for over limit vibration in the positions near the bearing: 1) closeness of the critical specd of the rotor system of the exciter rotor with the operating speed; 2) the effect from the dynamic characteristics of the seal ring; 3) the three support structure of the shaft system made coupling between the first mode of the exciter rotor and the second mode of the generator rotor.

The major dispute between Mack's and Wazzan's results of the linear instability for flat plate boundary layer lies in the effect of free stream Mach number on the viscous instability. In the paper, taking influence of the air thermodynamic properties into account a temporal eigenvalue problem of an adiabatic flat plate is calculated by a collocation technique. The numerical results indicate that the viscosity is only stablizing for the first mode and the second viscous mode is always stable at M=3....

The major dispute between Mack's and Wazzan's results of the linear instability for flat plate boundary layer lies in the effect of free stream Mach number on the viscous instability. In the paper, taking influence of the air thermodynamic properties into account a temporal eigenvalue problem of an adiabatic flat plate is calculated by a collocation technique. The numerical results indicate that the viscosity is only stablizing for the first mode and the second viscous mode is always stable at M=3. It is consistent with Mack's conclusion.

There exist variety of instability in three dimensional boundary layer on swept wing, the cross-flow instability is dominant The flow over rotating cone is typical three dimensional boundary layer It has been shown that the experimental and theoretical results of rotating cone can be used to model cross flow instability of swept wing At high speeds, where even the basic flow calculations of swept wing are a problem, owe to it′s simple geometry, rotating cone become a suitable and valuable model to study...

There exist variety of instability in three dimensional boundary layer on swept wing, the cross-flow instability is dominant The flow over rotating cone is typical three dimensional boundary layer It has been shown that the experimental and theoretical results of rotating cone can be used to model cross flow instability of swept wing At high speeds, where even the basic flow calculations of swept wing are a problem, owe to it′s simple geometry, rotating cone become a suitable and valuable model to study cross flow instability of high speed three dimensional boundary layer on swept wing In this paper, a rotating sharp cone which located in a supersonic/hypersonic free stream at zero attack is used as a model to study the cross flow instability of high speed three dimensional boundary layer The purpose of present work is to investigate the different instability mechanism of two and three dimensional boundary layers and effect of wall cooling on the instability The basic boundary layer flow is calculated using box scheme and the instability eigenvalue problem is solved by a fourth-order accurate two-point finite difference scheme Since the calssical approximation method of thermodynamic parameters of the air has not enough accuracy for numerical analysis of high speed instability problem, a high degree polynomial is used to imitate the dependence on temperature of viscosity, conductivity, Prandtl number and specific heat from experimental data The numerical results show that the growth rates of cross-flow first mode are larger comparing with those in two-dimensional case and the influence of cross flow decreases as Mach number increases but the influence of cross-flow on the second mode is weakly The results also show that the instability with cross flow cover a much wider range of unstable frequencies than those without cross flow and the growth rates of travelling waves are larger than stationary waves, the most unstable stationary wave is approximately perpendicular to potential flow direction If M e<4 3 the most unstable disturbance is the first mode, if M e>4 3 it is the second mode In three dimensional boundary layer the most unstable second mode is oblique, in two dimensional boundary layer is two-dimensiona; Cooling the wall stabilizes the first mode, destabilizes the second mode