Possibility of Reducing Spar-Type FOWT Hydrodynamic Response Using a Torus Structure With Annular Flow

Gyroscopic motion is considered as an appropriate approach to suppress the shaking motion of rigid bodies. Its spatial orientation is also used to make gyro compasses in the marine industry. In this paper, the floating offshore wind turbine (FOWT) was designed based on potential theory and gyroscopic effect and rotational axis retention effect were also considered, so that FOWT could obtain better hydrodynamic response. However, gyroscopic motion was generated through an annular flow in the internal torus instead of rigid body rotation. The scale of torus and the angular velocity of the annular flow were the design parameters that this article was eager to understand obviously. By vast quantity of calculations, the suitable range of design parameters was obtained.

Substantial condition for the fourth first integral of the rigid body problem

The aim of this article is to study the possibility of obtaining the fourth integral for the motion of a rigid body about a fixed point in the presence of a gyrostatic moment vector. This problem is governed by a system consisting of six nonlinear differential equations from first order, as well as three first integrals. A most important condition for a function F, depending on all the body variables, to be that integral is presented. This work can be considered a mainstreaming of previous works. The importance of this work lies in several applications of the rigid body problem and gyroscopic motion in different areas, such as physics, engineering and industrial applications, for example, in aircraft specially designed to use the auto-pilot function, calculating aircraft turns about various axes of operation (pitch, yaw and roll), and maintaining aircraft orientation.

Improvement and Realization of Miniature Flexible Gyro in the Photoelectric Platform

Generally ,it was precession of flexible gyroscopic not gyroscopic nutation which was just considered in engineering design. However, in photoelectric stabilized platform, this nutation characteristics of angular position flexible gyro has been restricting the stabilized accuracy of platform seriously. In this paper, firstly the output characteristics of a miniature flexible gyro was measured by characteristic of gyroscopic motion, four main kinds of frequency components in output characteristics was analysed. The methods were realized in the miniature flexible gyroscope in the laboratory by adopting the two measures of the secondary trap circuit and improvement of torque component.Test results showed that, the improvements made nutation frequency of gyro and envelope at 40Hz converged fastly , and the output noise of gyro angular position was decayed to more than15dB. In the end, the gyro was applied to chariot photoelectric stabilized platform ,the isolation of platform and carrier got improved from 1~2mil to 0.3mil.

Electromagnetic Gyroscopic Motion

A problem of the gyroscopic motions around a fixed point, under the action of a gyrostatic moment vector, in presence of electromagnetic field and Newtonian one, is considered. The small parameter technique is used to investigate the periodic solutions for the derived equations of such motion problem. A geometric interpretation of motion will be given in terms of Euler’s angles (θ,ψ,ϕ). Computer programs are carried out to integrate the attained quasilinear autonomous system using a fourth-order Runge-Kutta method. A comparison between the obtained analytical solutions and the numerical ones is investigated to calculate the errors between them.