From left, Midn. 1/C Gregory Knopik, Grant LeMaster and Matthew Hartsog mount sensor equipment to a Yard Patrol craft. Their research is geared towards investigating ship air-wake impact on naval helicopters. Photo courtesy of the Naval Academy Mechanical Engineering Department.

As a helicopter approaches a ship for landing, one of the items on the landing checklist is to ensure that the winds are within safe limits. For each series of naval aircraft and each class of air-capable ship, Naval Air Systems Command (NAVAIR) produces a diagram called a wind envelope which depicts the wind speeds and directions relative to the centerline of the ship at which the aircraft is permitted to land. Too much of a cross or tail wind and the aircraft can become difficult or impossible to control over the flight deck, putting both the aircrew and ship’s company in jeopardy.

Until now NAVAIR has created these wind envelopes using test and evaluation flights during the ship’s initial flight deck certification. Despite their high level of training and experience, this remains a dangerous evolution for test pilots and their aircrews. However, thanks to the efforts of a team of dedicated Midshipmen, the necessity of test flights to create wind envelopes could become a thing of the past.

The purpose of the project, a $500,000, three-year research program funded by the Office of Naval Research, is to develop computational fluid dynamics tools to help determine helicopter launch and recovery wind envelopes for naval vessels.

‘‘Our Midshipmen are making significant contributions to the success of the research,” said Capt. Murray Snyder, a permanent military professor in the Mechanical Engineering Department and the project director. ‘‘They are performing the work that experienced graduate students at a civilian university would perform. The project is much farther along due to the hard work and dedication of the Midshipmen.”

Last summer, Midn. 1⁄C James Golden, a mechanical engineering major, and Midn. 1⁄C William Stillman, an aerospace engineering major, completed internships at NAVAIR during which they finished the preliminary flow simulations of ship air-wakes using a state-of-the-art, high-performance computing cluster of over 100 separate processors.

Their supervisors were so impressed with the quality of work performed by the Midshipmen that NAVAIR has requested 10 more Midshipman interns for summer 2010.

The preliminary flow analysis completed by Golden and Stillman is currently being used to help determine the placement of sensors and test equipment installed on a Naval Academy yard patrol (YP) craft. This test equipment, which includes fog generators, velocity measuring equipment and other sensors required for flow-field visualization, requires a great deal of support equipment.

The support equipment was designed, constructed and installed by Midshipmen from the Mechanical Engineering Department, Midn. 1⁄C Gregory Knopik, Grant LeMaster, and Joshua Shishkoff and Midn. 2⁄C Matthew Hartsog. They also modified YP 676 with a flight deck on the aft section which will eventually be used to test-land unmanned rotorcraft.

In addition to building and installing it, the team of Midshipmen also runs the test equipment and the video capture system, and has drafted computer codes to collect and analyze the data.

‘‘The Midshipmen are vital members of our research team and continued Midshipmen involvement in the future will be critical to our success,” said Snyder.

The ship air-wake research group also includes Assistant Professors Cody Brownell and Luksa Luznik from the Mechanical Engineering Department, Associate Professor David Miklosovic and Visiting Professor John Burks from the Aerospace Engineering Department and Professor Greg White from Naval Architecture and Ocean Engineering Department.