Dynamic simulation of buoyancy engine of underwater glider based on experimentation
As a key component for underwater gliders, the buoyancy engine plays an important role in the operation of gliders, the performance of which directly affects the monolithic reliability. In this paper, to lower costs of research on the buoyancy engine, a dynamic simulation is established by AMEsim software, in which the performance of the low-pressure boost gear pump and that of the high-pressure hydraulic axial piston pump are analyzed. And based on the simulation results, an experiment is designed to verify validity of the simulation. The method of buoyancy engine simulation in this paper may provide a valuable reference for designers.
AUV Buoyancy Regulating Device Design and Simulation Analysis
Under the influenced of the seawater temperature, salinity and depth, AUVs buoyancy would change when it works in deep ocean, causing energy consumption and operating performance declining. To deal with this problem, buoyancy regulating device is developed, which is of important significance for the development of large voyage and high submergence depth AUV. An oil capsule buoyancy regulating device is designed in this paper, which utilizes the flexibility of oil capsule. The oil capsule volume changes when absorbing or expulsing oil. The gas volume variation in pressure tank is measured in order to calculate the amount of the buoyancy regulation indirectly. The accuracy and sensitivity for measuring the gas volume variation is analysed. To verify the feasibility of the designed oil capsule buoyancy regulating device, a simulation experiment of this hydraulic system is performed within AMESim.
Continuous hyperspectral absorption measurements of colored dissolved organic material in aquatic systems.
The majority of organic carbon in the oceans is present as dissolved organic matter (DOM); therefore understanding the distribution and dynamics of DOM is central to understanding global carbon cycles. Describing the time-space variability in colored dissolved organic matter (CDOM) has been difficult, as standard spectrophotometric methods for CDOM determination are laborious and susceptible to methodological biases. Previously, measurements of CDOM absorption in discrete water samples by use of a liquid-waveguide capillary cell (LWCC) compared favorably with measurements made with a benchtop spectrophotometer. Given this, we focused on automating the LWCC technique to improve our spatial and temporal sampling capabilities for CDOM. We found strong correlations between CDOM absorption spectra collected from discrete water samples using standard methods and selected corresponding CDOM spectra collected by the automated LWCC system. The near-continuous measurements by the LWCC system made it possible to map the temporal, spatial, and spectral variability of CDOM absorption along the ship track.