A Fault-Tolerant Level Damping Algorithm for Marine INS

When the measurement error of the external reference velocity changes dramatically, the traditional level damping for marine INS needs to cut off the damping to maintain the navigation accuracy. The level channel has a large overshoot oscillation during the variable damping instantaneous, which results in obvious position deviation. In order to solve this practical problem, a damping model is established outside the INS. The most obvious advantage of the algorithm is that the damping algorithm does not affect the inertial navigation solution. The fault-tolerant algorithm realizes the automatic damping switch according to the external reference velocity error variation criterion, which avoids the velocity oscillation and position deviation. Compared with traditional methods, the algorithm presented in this paper has higher reliability and better environmental adaptability. The effectiveness of the algorithm is verified by the actual navigation test data.

Surface temperature and free-stream velocity oscillation effects on mixed convention slip flow from surface of a horizontal circular cylinder

The present phenomena address the slip velocity effects on mixed convection flow of electrically conducting fluid with surface temperature and free stream velocity oscillation over a non-conducting horizontal cylinder. To remove the difficulties in illustrating the coupled PDE, the primitive variable formulation for finite dif?ference technique is proposed to transform dimensionless equations into primitive form. The numerical simulations of coupled non-dimensional equations are exam?ined in terms of fluid slip velocity, temperature, and magnetic velocity which are used to calculate the oscillating components of skin friction, heat transfer, and cur?rent density for various emerging parameters magnetic force parameter, ?, mixed convection parameter, ?, magnetic Prandtl number, ?, Prandtl number, and slip factor, SL. It is observed that the effect of slip flow on the non-conducting cylinder is reduced the fluid motion. A minimum oscillating behavior is noted in skin friction at each position but maximum amplitude of oscillation in heat transfer is observed at each position ? = ?/4 and 2?/3. It is further noticed that a fluid velocity increas?es sharply with the impact of slip factor on the fluid-flow mechanism. Moreover, due to frictional forces with lower magnitude between viscous layers, the rise in Prandtl number leads to decrease in skin fiction and heat transfer which is physi?cally in good agreement.

Surface temperature and free-stream velocity oscillation effects on mixed convention slip flow from surface of a horizontal circular cylinder

The present phenomena address the slip velocity effects on mixed convection flow of electrically conducting fluid with surface temperature and free stream velocity oscillation over a non-conducting horizontal cylinder. To remove the difficulties in illustrating the coupled PDE, the primitive variable formulation for finite dif?ference technique is proposed to transform dimensionless equations into primitive form. The numerical simulations of coupled non-dimensional equations are exam?ined in terms of fluid slip velocity, temperature, and magnetic velocity which are used to calculate the oscillating components of skin friction, heat transfer, and cur?rent density for various emerging parameters magnetic force parameter, ?, mixed convection parameter, ?, magnetic Prandtl number, ?, Prandtl number, and slip factor, SL. It is observed that the effect of slip flow on the non-conducting cylinder is reduced the fluid motion. A minimum oscillating behavior is noted in skin friction at each position but maximum amplitude of oscillation in heat transfer is observed at each position ? = ?/4 and 2?/3. It is further noticed that a fluid velocity increas?es sharply with the impact of slip factor on the fluid-flow mechanism. Moreover, due to frictional forces with lower magnitude between viscous layers, the rise in Prandtl number leads to decrease in skin fiction and heat transfer which is physi?cally in good agreement.

The Finite Difference Technique for Modelling of Pipe System Vibroacoustical Characteristics

The finite difference technique of vibroacoustical pipeline characteristics are developed. The technique allows calculations vibroacoustical characteristics of pipe with the axial line lying in one plane under force excitation by oscillating fluid flow. The technique is based on the solving differential equation system of interaction between solid and oscillating fluid in the pipeline. Solution was done for transient non-stationary nonlinear differential equation system. The boundary conditions for fluid is a parameter combination of complex pressure oscillation amplitude of pipeline inlet section, complex pressure oscillation amplitude of pipeline outlet section, complex velocity oscillation amplitude of pipeline inlet section, complex velocity oscillation amplitude of pipeline outlet section, load impedance, input impedance. The boundary conditions for solid is bonding of the pipeline. Time response of the pipeline vibration are resulted of these techniques. The mathematical technique computational coast is 3 orders less than Ansys technique. The method is developed for pipeline diameter much smaller than acoustic wavelength in a fluid. It is actual for aircraft pipelines, pipes of power plants, mobile machines and pipes of stationary processing machines.