SITIS Archives - Topic Details
Program:  SBIR
Topic Num:  AF071-151 (AirForce)
Title:  Improved Grid Fin Manufacturing Techniques
Research & Technical Areas:  Materials/Processes, Weapons

 The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), which controls the export and import of defense-related material and services. Offerors must disclose any proposed use of foreign nationals, their country of origin, and what tasks each would accomplish in the statement of work in accordance with section 3.5.b.(7) of the solicitation.
  STATEMENT OF INTENT: Low cost manufacturing contributes to lower munition total cost
  Objective:  To identify and develop improved, low-cost grid fin manufacturing techniques for miniature air-launched munitions.
  Description:  Grid fins have been shown to improve munition performance by reducing control actuator hinge moments, providing linear aerodynamics, and by compact carriage in internal bays through ease of fin folding. The former Soviet Union applied grid fins for years on a number of their strategic missiles and air-to-air missile designs. More recently, the United States has applied grid fins to a number of laboratory munition programs, as well as for the Massive Ordnance Air Blast (MOAB) acquisition program. A draw back of these programs has been the high cost of manufacture of the fins. Typically the fins were manufactured through milling of aluminum billets, an expensive method. Some progress has been made in the use of water jet milling, but the costs still exceed those of traditional planar fins. The purpose of this topic is to explore new methods of grid fin manufacture that will lead to a net zero cost increase over conventional techniques.

  PHASE I: Identify potential materials (both metals and composites), manufacturing, and assembly/joining methods as applied to a representative grid fin design. Demonstrate at a coupon level the ability to meet the tight tolerances associated with grid fin construction. Project fin cost-to-produce estimates.
  
  PHASE II: Demonstrate several, preferred manufacturing, and assembly/joining methods on a full scale fin design. Determine manufacturing cost estimates on these preferred methods. Conduct loads testing to evaluate ability to endure flight conditions.

  DUAL USE COMMERCIALIZATION: Military application: Applications of low cost manuafacturing methods could be extended to cruise missile and UAV programs. Commercial application: Automotive and commercial aviation industries could benefit from the novel composite material manufacturing methods, as applied to complicated shape components.

  References:  1. Washington, Wm. David, and Mark S. Miller, "Grid Fins - A New Concept for Missile Stability and Control," AIAA 93-0035. 2. Washington, Wm. David, Pamela F. Booth, and Mark S. Miller, "Curvature and Leading Edge Sweep Back Effects on Grid Fin Aerodynamic Characteristics," AIAA 93-3480. 3. Washington, Wm. David, and Mark S. Miller, "An Experimental Investigation of Grid Fin Drag Reduction Techniques," AIAA 94-1914. 4. Burkhalter, John E., "Grid Fins for Missile Applications in Supersonic Flow," AIAA 96-0194. 5. Fournier, "Wind Tunnel Investigation of Grid Fin and Conventional Planar Control Surfaces," AIAA 2001-0256.

Keywords:  grid fins, aerodynamic control, composite manufacturing, lattice fins, composite assembly, composite joining methods

Questions and Answers:
Q: Is welding and brazing or similar joining processes allowed in the manufacturing of the grind fins?
A: The emphasis of this topic is on low cost manufacturing. Joining processes typically contribute measurably to the cost of manufacture. If novel welding and/or brazing methods contribute to reducing cost of manufacture of grid fins comparable to the cost of traditional planar fins, which are simple geometric shapes, then there is interest in this technology and it would be allowed.

We are not excluding any joining processes. However, whatever the process it is desired to minimize or possible eliminate any fillets at the intersection of the grids.
Q: Is welding and brazing or similar joining processes allowed in the manufacturing of the grind fins?
A: The emphasis of this topic is on low cost manufacturing. Joining processes typically contribute measurably to the cost of manufacture. If novel welding and/or brazing methods contribute to reducing cost of manufacture of grid fins comparable to the cost of traditional planar fins, which are simple geometric shapes, then there is interest in this technology and it would be allowed.

We are not excluding any joining processes. However, whatever the process it is desired to minimize or possible eliminate any fillets at the intersection of the grids.

Record: of