Use of Hinged Strakes for Lateral Control at High Angles of Attack.
Abstract
This thesis investigated the feasibility of using a portion of the leading edge (LE) strake hinged along the longitudinal axis as a roll control device for a high performance aircraft at high angles of attack (AOA). A wind tunnel test was conducted to gather static force and moment data for use in a six degree of freedom computer simulation. Asymmetric strake deflections, both dihedral and anhedral, were investigated. The longitudinal coefficients were little affected by strake deflection, but the lateral directional coefficients showed a nonlinear, but repeatable, behavior with strake deflection. Comparisons to be published data indicate that the strakes produce similar behavior for different aircraft designs. Simulations of the aircraft response to the strakes showed that an improvement over current roll performance could be obtained by combining the positive strake deflection with the ailerons up to 38 deg. AOA, after which the strakes alone produced the best roll performance. Sideslip and AOA must be closely controlled or the air-craft will either not roll, or will depart during the roll. The roll performance using hinged strakes at high AOA is compared to roll performance using differential (LE) flaps. The diffential LE flaps produce comparable roll rates with less sideslip than produced by the hinged strakes. However, the possibility exists of combining hinged strakes with differential (LE) flaps for improved roll performance.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1985
- Accession Number
- ADA158005
Entities
People
- R. E. Erb
Organizations
- Air Force Institute of Technology