Accession Number:

ADA021713

Title:

Spectral Gust Response for an Airplane with Vertical Motion and Pitch

Descriptive Note:

Final technical rept. 1 Nov 1974-30 Sep 1975

Corporate Author:

AERONAUTICAL RESEARCH ASSOCIATES OF PRINCETON INC NJ

Personal Author(s):

• Houbolt, John C.
• Williamson, Guy G.

Report Date:

1975-11-01

Pagination or Media Count:

50.0

Abstract:

Gust response analysis based upon power spectral techniques is made for an airplane having the two degree of freedom of vertical motion and pitch. A rather unique formulation of the equations of motion is made, wherein the aerodynamic loads are treated as dependent variables, as are the vertical and pitching motions. Nonsteady lift effects, finite span effects, tail downwash effects, and gust lag effects are all taken into account over the complete frequency range of concern. It is found that the inclusion of pitch considerably alters the response from that found for the case of vertical motion alone. In general, pitch is found to cause a significant attenuation of the response at low frequencies. One of the important findings of the study is the fact that the gust response for the two-degree-of-freedom case can be expressed in a form which is essentially independent of the integral scale of turbulence. Variations in geometric parameters of the airplane, such as tail moment arm, or radius of gyration in pitch, are considered to obtain an idea of the sensitivity of the gust response to these parameters.

Descriptors:

• *PITCH(MOTION)
• *AIRFRAMES
• *GUSTS
• PARAMETRIC ANALYSIS
• TAIL ASSEMBLIES
• DYNAMIC RESPONSE
• ATMOSPHERIC MOTION
• MOMENTS
• POWER SPECTRA
• LIFT
• SPECTRUM ANALYSIS
• DOWNWASH

Subject Categories:

• Aerodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE