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Vachon, W. A.

Publications and source records attributed to Vachon, W. A..

An overview of large wind turbine tests by electric utilities

A summary of recent plants and experiences on current large wind turbine (WT) tests being conducted by electric utilities is provided. The test programs discussed do not include federal research and development (R&D) programs, many of which are also being conducted in conjunction with electric utilities. The information presented is being assembled in a project, funded by the Electric Power Research Institute (EPRI), the objective of which is to provide electric utilities with timely summaries of test performance on key large wind turbines. A summary of key tests, test instrumentation, and recent results and plans is given. During the past year, many of the utility test programs initiated have encountered test difficulties that required specific WT design changes. However, test results to date continue to indicate that long-term machine performance and cost-effectiveness are achievable.

Vachon, W. A.↗

Simple and effective method to lock buoy position to ocean currents

Window-shade drogue, used with drifting buoys to keep them moving with current at speed as close to that of current as possible, has drag coefficient of 1.93 compared to maximum of 1.52 for previous drogues. It is remarkably simple to construct, use, and store.

Vachon, W. A.↗

Scale model testing of drogues for free drifting buoys

Instrumented model drogue tests were conducted in a ship model towing tank. The purpose of the tests was to observe and measure deployment and drag characteristics of such shapes as parachutes, crossed vanes, and window shades which may be employed in conjunction with free drifting buoys. Both Froude and Reynolds scaling laws were applied while scaling to full scale relative velocities of from 0 to 0.2 knots. A weighted window shade drogue is recommended because of its performance, high drag coefficient, simplicity, and low cost. Detailed theoretical performance curves are presented for parachutes, crossed vanes, and window shade drogues. Theoretical estimates of depth locking accuracy and buoy-induced dynamic loads pertinent to window shade drogues are presented as a design aid. An example of a window shade drogue design is presented.

Vachon, W. A.↗