Stability of subsea pipelines during large storms

Seismic Stability of Subsea Tunnels Subjected to Seepage

Strength reduction method and ADINA software are adopted to study the stability of submarine tunnel structures subjected to seepage and earthquake under different seawater depths and overlying rock strata thicknesses. First, the excess pore water pressure in the rock mass is eliminated through consolidation calculation. Second, dynamic time-history analysis is performed by inputting the seismic...

Ionospheric redistribution during geomagnetic storms

[1]The abundance of plasma in the daytime ionosphere is often seen to grow greatly during geomagnetic storms. Recent reports suggest that the magnitude of the plasma density enhancement depends on the UT of storm onset. This possibility is investigated over a 7year period using global maps of ionospheric total electron content (TEC) produced at the Jet Propulsion Laboratory. The analysis confir...

Stability Results for Convection in Thawing Subsea Permafrost

Penetrative convection is investigated in a porous medium bounded above by the ocean bed and below by the interface of the thawing permafrost ground. Such convection ow is observed oo the coast of Alaska. The physical model for the thawing subsea permafrost is that of Harrison and Swift 8], with the eld variables: the brine velocity, the temperature and the salinity. We simplify the problem by ...

Large Disturbance Stability Analysis of Wind Turbine Implemented with DFIG

As one of the most promising Distributed Generation (DG) sources, wind power technology has been widely developed in recent years. Doubly fed induction generator (DFIG) is currently employed as one of the most common topologies for wind turbine generators (WTGs). This generator operates as a synchronous/asynchronous hybrid generators. Therefore, it is necessary to power engineers find understan...

Large-scale atmospheric circulation patterns associated with the occurrence of severe storms Zab basin