Passive Cooling for Aircraft Carrier Jet Blast Deflectors (JBD)
Navy SBIR 2019.2 - Topic N192-100
NAVSEA - Mr. Dean Putnam - firstname.lastname@example.org
Opens: May 31, 2019 - Closes: July 1, 2019 (8:00 PM ET)
TECHNOLOGY AREA(S): Materials/Processes
ACQUISITION PROGRAM: PMS 312 In-Service Aircraft Program Office.
OBJECTIVE: Develop a capability for passive cooling of Aircraft Carrier Jet Blast Deflectors.
DESCRIPTION: Commercial jet blast deflectors are raised and lowered by hydraulic arms; are actively cooled; and range in complexity from stationary concrete, metal, or fiberglass fences to heavy panels. The decks of aircraft carriers are presently equipped with pivotally mounted Mark 7 Jet Blast Deflector (JBD) Systems that function to dissipate jet exhaust of aircraft undergoing catapult launch. Aircraft Carrier JBDs are cooled by active cooling systems that tap the fire mains (i.e., fire suppression water systems) to circulate seawater through water lines within the deflector panel. This active cooling system imposes significant corrosion effects and burdensome maintenance problems as well as a complicated constructional design and increased associated costs. The cost of JBD maintenance on aircraft carriers is in the tens of millions of dollars for the fleet. There are additional operational and aging problems for the equipment involved because of the high temperatures and the flow speeds of exhaust plumes from the aircraft. Passively cooled JBD systems will reduce Carrier operating and maintenance cost by 40%.
Reducing operating and maintenance costs for Aircraft Carriers can be achieved through avoidance of maintaining the seawater cooling lines by reducing and burdensome maintenance problems due to corrosion caused by the seawater cooling lines.
The orientation of aircraft carrier catapults requires that the hot exhaust gases of the jet aircraft turning up to full power during launch operations are deflected so as not to cause heat and blast damage to other aircraft, equipment, and personnel on the flight deck. As such, the JBD must be capable of withstanding both the heat and pressure forces that impinge on its surface as a result of the aircraft blast. The JBD, which consists of a series of water cooled panels, achieves this purpose. The JBD, when in the flush deck position, allows an aircraft to be taxied over it and into launch position. As soon as the aircraft is forward of the JBD, the operation actuates the hydraulic system to raise the JBD for aircraft turn up. The JBD must allow for ease of maneuvering the aircraft on the flight deck (so as to position it for launch) as well as be capable of absorbing any landing or rollover loads. The final capability requires rapid dispersion of heat after an aircraft launch.
The Navy is seeking a passive JBD System (i.e., a system that does not require active water cooling) with physical dimensions (height 14 feet, width 36 feet) that allow for installation in a Flight Deck Pit identical in length, width, and depth to those that house the currently deployed Mark 7 JBD System. Electrical power is available for solutions that require it, but high voltage solutions will add safety concerns. The passive JBD System will consist of a heat deflector panel, a structural panel, and associated actuating mechanisms and control systems. The aircraft jet blast will impinge directly on the heat deflector. As such, the heat deflector panel will have a surface profile and inclination (in the fully raised position) that will be adequate to protect any Naval Aircraft (present and future) located behind the JBD, as well as protecting the structural panel. In addition, the heat deflector panel surface will prevent recirculation of the jet blast into the jet intakes of the aircraft located in front of the JBD. The heat deflector panel surface attitude to the Catapult Centerline (for each catapult installation) will be identical to that of the currently deployed Mark 7 Jet Blast Deflector Panel. The distance of the heat deflector panel hinge line to the Catapult Station “0” location will be identical to that of the currently deployed Mark 7 Jet Blast Deflector Panel. The structural panel will completely cover the Flight Deck Pit (and any system components located in it). The JBD System must withstand aircraft rollovers and landings, Foreign Object Debris (FOD) impingement, and any potential strikes from aircraft hook points or accidentally dropped equipment normally used by flight deck personnel. The JBD System will be exposed to thermal cycling, weather, sea states seawater spray, countermeasure wash-down, JP-5 spills, and other wear and tear. The passively cooled JBD system must not be subject to suffer structural damage under flight operations and must have a sufficiently high cool-down rate to achieve 200°F tire-
rollover to meet required sortie rates. The tire-rollover surface of the JBD system must have non-slip characteristics identical to those provided by the cooling modules of the currently deployed Mark 7 JBD.
System Requirements Information: Temperature profile and jet diameters will depend on the specific aircraft but generally the JBDs are designed to handle 3182 F (1750 C) for up to 90 seconds. The new system must have a sufficiently high cool-down rate to achieve a 200-degree F tire-rollover surface temperature within 10 seconds of completion of an aircraft launch. All JBDs are currently inclined at a 50-degree angle to the flight deck, but vary in distance. The distance is taken from catapult station 0 (zero) to the JBD hinge line. Catapult 1 is 68 feet, Catapult 2 is 58 feet, Catapult 3 is 68 feet and Catapult 4 is 60 feet (These are minimum distances that can vary ship to ship). Station zero is where the aircraft nose gear hooks up to the catapult, so aircraft nozzle distance to the JBD hinge line will depend on the geometry of the aircraft. With the future use of vertical takeoff aircraft, consideration is needed for the vertical impingement of hot gas temperature at a much shorter distance. Ambient conditions will be Flight operating conditions at sea level.
Dimensions: the current Mark 7 Mod 0 JBD dimensions are 36 feet in length by a raised height of 10.7 feet. The recess in the deck where the JBD lowers into has a thickness of roughly 9 inches. It raises to an angle of 50 degrees relative to the flight deck. For ease of retrofit into existing carriers, any new JBD cannot exceed these dimensions.
Weight: Any new JBD cannot weigh more than the current Mark 7 Mod 0 JBD which weighs roughly 53,000 lbs. Note that any weight reduction relative to the current system will be a benefit.
Thermal Shock Endurance: The JBD must withstand 60 seconds of idle thrust (600 degrees F total temperature at 500 feet/sec velocity and 3300 lbs. of thrust), followed by 60 seconds of military thrust (2230 degrees F total temperature at 1860 feet/sec velocity and 31,000 lbs. of thrust), which is followed by 30 seconds of combat thrust or “afterburner” (3182 F (1750 C) – degrees total temperature at 3000 ft/sec velocity and 50,000 lbs. of thrust) with a return to idle thrust for 60 seconds in the case of a suspension of launch.
Jet Blast Impingement: The surface must withstand an impingement of 3000 ft/sec velocity by Foreign Object Debris (FOD) of an average 39.6 grams weight, 9.2 mm height, 63.9 mm width and 8.6 mm thickness. In addition, the surface must withstand impingement by micro-FOD at 3000 ft/sec velocity, and abrasion from Arresting Gear cable during normal operations thereof.
Cooling Capabilities: The new system must have a sufficiently high cool-down rate to achieve a 200-degree F tire- rollover surface temperature within 10 seconds of completion of an aircraft launch.
Surface Slip Characteristics: To provide adequate traction for the tires of aircraft and tow tractors, the entire flight deck, including the JBD, is covered with a non-skid compound of synthetic binders and abrasive particles. Any new JBD surface must either have the same slip resistance characteristics of current non-skid or allow for non-skid to adhere to and be removed from the surface. (Current non-skid is applied per MPR 1057).
Resistance to Contaminants: The flight deck, and the JBD in particular, is regularly exposed to hydraulic oils, JP-5 aviation fuel, AFFF fire-fighting foam and cleaners. The JBD surface must be resistant to these contaminants.
Shock: The JBD System shall meet the requirements of, and be tested in accordance with, MIL-S-901D shock, grade
A. The JBD System shall be capable of sustaining static loads resulting from shock loads while the JBD is in the fully raised position.
Vibration: The JBD System shall meet the Type I and 2 environmental vibration requirements of MIL-STD-167-1 up to and including 21 cycles per second.
PHASE I: Develop a concept for passively cooled Jet Blast Deflector systems that describes how the system will be implemented, provides cost ranges for the systems, and provides notional shipboard implementation. Establish feasibility by material testing and/or through analytical modeling. Develop a Phase II plan. The Phase I Option, if exercised, should include the initial specifications and capabilities for the system to be developed in Phase II.
PHASE II: Develop a prototype Passive JBD system for delivery and evaluation to determine its capability in meeting the performance goals defined in the Phase II SOW and the Navy requirements for passively cooled Jet Blast Deflector systems. Demonstrate system performance through prototype evaluation and testing over the required range of parameters including numerous deployment cycles to verify test results. Using evaluation results, refine the prototype into an initial design that will meet Navy requirements. Prepare a Phase III development plan to transition the technology to Navy use.
PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the technology for Navy use. Support the Navy for test and validation to certify and qualify the system for Navy use. The system should transition onto Carrier platforms.
Other organizations such as Integrated Weapons Systems may benefit from this technology in their efforts to deflect or minimize the adverse effects of exhaust blast. This technology may also reduce maintenance and operations costs for commercial aviation. Government and commercial space programs may also benefit from the technology.
1. Naval Air Warfare Center Jet Blast Deflection Site. http://www.navair.navy.mil/nawcad/index.cfm?fuseaction=home.content_detail&key=7E0AD2EF-3FAB-41DE- 8274-4B99F2404430
2. MIL STD 810 Rev. E, (1989). http://everyspec.com/MIL-STD/MIL-STD-0800-0899/MIL-STD-810E_13775/
3. Naval Air Training and Operating Procedures Standardization (NATOPS) General Flight and Operating Instructions. http://www.public.navy.mil/airfor/vaw120/Documents/CNAF%20M-3710.7_WEB.PDF
4. Zope, BS and Talikoti, RS. “Jet Blast Deflector Fence.” International Journal of Modern Trends in Engineering and Research (IJMTER); Volume 02, Issue 07, July– 2015. https://www.ijmter.com/papers/volume-2/issue-7/jet- blast-deflector-fence.pdf
5. Fischer, Eugene C., Sowell, Dale A., Wehrle, John, and Cervenka, Peter O. “Cooled Jet Blast Deflectors For Aircraft Carrier Flight Decks.” U.S. Patent 6,575,113, Issued June 10, 2003. https://patentimages.storage.googleapis.com/23/3a/fb/099ebab7f56fe0/US6575113.pdf
KEYWORDS: Aircraft Launch and Recovery Equipment; ARLE; Jet Blast Deflector; JBD; Jet Blast Deflector Passive Cooling; Jet Blast Deflector Active Cooling; Jet Blast Deflector Test Site; Jet Blast Deflector Structural, Hydraulic and Cooling Systems