The Hydrodynamic Coefficient Analysis and Motion Control of the Lingyun Moveable Lander

A moveable lander has the advantages of low cost and strong controllability and is gradually becoming an effective autonomous ocean observation platform. In this study, the hydrodynamic property of the Lingyun moveable lander, which has completed experiments in the Mariana Trench in 2020, is analyzed with the semiempirical method and computational fluid dynamic (CFD) method. We calculate the inertial hydrodynamic coefficients and viscous hydrodynamic coefficients of the lander. The results show that the CFD can provide the hydrodynamic property for the moveable lander’s design. The dynamic equations and kinematic equations are completely constructed combined with the hydrodynamic coefficients. Subsequently, this paper utilized the PID control method and S control method to control the motions of the lander. The simulation results show that the methods accurately follow the preplanned path.

Numerical Simulation Method of Leakage for Lip Seal

Lip seal, widely used in industries, is usually applied to seal pressure chamber. Leakage of lip seal has always been a primary problem. In the present study, hydrodynamic property of lubricating film and elastic deformation of sealing lip are analyzed numerically by coupling Reynolds equation and elastic deformation equation. A numerical model for calculating leakage is proposed, results of the analysis will be of help to interference design and structure optimization for auto water pump bearing’s seal.

Distribution Regularity of the Wide-Spread Sandstone of He8 Fomation in Ordos Basin

Based on previous studies, the formation mechanism of large-area distribution of sandstone was studied from the views of source supply, ancient terrain, hydrodynamic property and frequent changes of lake level. Sedimentation simulating experiment revealed that the controlling factors of large-area distribution of sandstone include ancient terrain, lake level, source supply, flow, velocity stream. The ancient terrain slope and shallow lake are important geological background, strong source supply is material basis, intersected multi-water is an important way, high velocity stream is considerable driving force, frequent changes of lake level is important controlling factor.

Short-term volume and turgor regulation in yeast

Volume is a highly regulated property of cells, because it critically affects intracellular concentration. In the present chapter, we focus on the short-term volume regulation in yeast as a consequence of a shift in extracellular osmotic conditions. We review a basic thermodynamic framework to model volume and solute flows. In addition, we try to select a model for turgor, which is an important hydrodynamic property, especially in walled cells. Finally, we demonstrate the validity of the presented approach by fitting the dynamic model to a time course of volume change upon osmotic shock in yeast.