SUMMARY AND CONCLUSIONS

The WTEC team did not see much that was new or revolutionary. Most of the technologies presented to the team were conventional. However, one must keep in mind the fact that an extremely time-limited and busy visit schedule permitted very little in-depth discussions with the hosts. What was impressive was the numbers of units either built or designed.

Another problem in attributing developments to specific organizations was the question of whether the organizations were simply systems integrators or had technologies transferred to them for other reasons. Thus if an institute claimed to be using a certain type of energy system, it was not always clear whether the system was that organization's original development. This is the kind of detail that surely would have emerged if more time had been available at the sites.

Energy and Power Systems

A wide variety of energy and power systems were shown to the WTEC team. Most of this work was not state of the art. The WTEC team was shown or made aware of 30 to 40 manned submersible/submarine concepts or actual hardware. In almost every case, conventional batteries were the chosen energy source. This is also validated by the fact that none of the team members was briefed on any details of battery developments.

With respect to nuclear power sources, the situation was somewhat different. Team members were briefed on reactor applications from 45,000 kW to 6 kWe, and actually saw the 6 kWe thermoelectric unit in operation. Among the unique, seriously proposed applications were a large (6,000 kW) unattended seafloor system (ROSSHELF) and a small simple unit built for a research submarine (Ocean Shuttle). In addition, a 15,000 kW reactor has been proposed for the service and maintenance submarine for the ROSSHELF complex. All of this design activity for nuclear reactors is not surprising considering the extensive numbers and varieties of nuclear submarines that were developed for the Soviet Navy. Defense conversion is now bringing much of all this knowledge into the civil sector.

Fuel cell development in the countries visited did not show significant advancements over the state of the art. Energia seems to have acquired numerous hours on units developed for the space program. This base of experience could help the company develop cost-effective, reliable units for commercial applications.

Hydrodynamics

The most interesting visit in this technical area was to the Hydromechanics Institute at Kiev, Ukraine. The institute's work in developing and testing high-speed projectiles in water is very advanced. However, it does not have much application to deep submersibles. It is difficult to see how movement of a body at speeds of Mach 1 would have a commercial application.

In the United Kingdom, hydrodynamics work for the Autosub project is important for getting hull shapes for long-duration mission vehicles. Reduction of drag converts to longer mission times and/or less energy usage. However, even this hydrodynamics work is pretty much state of the art. Perhaps the new aspect of this work is open ocean testing to determine drag induced by particulates in the sea, marine growth during long missions, and the effect of small-scale turbulence on the vehicle.

Propulsion

The WTEC teams saw, or were told about, a wide variety of design approaches for propulsion systems (propellers, thrusters, ducted devices, etc.). However, most of it was not particularly new. An exception may be the MHD work being done by RRC Kurchatov, which is interesting because the power levels are said to be much higher than those of the Japanese system being tested in the experimental vessel Yamato.

The Institute of Hydromechanics in Kiev, Ukraine is doing imaginative work in developing a mechanical analog of fish propulsion. While this general line of work has been done many times before, it has seldom resulted in a large-scale, seagoing test model like the one developed by the institute. Unfortunately, the WTEC team was not briefed on the specific performance of this unit, so efficiency is unknown.

Deacon Laboratory's Autosub program in the U.K. has resulted in some excellent advancements in propulsion motors for vehicles. Moog Controls' contra rotating motor and the design of its ceramic seals will be useful contributions to the development of other submersibles.


Published: June 1994; WTEC Hyper-Librarian