Accession Number:

AD0623081

Title:

PREDICTION OF RE-ENTRY VIBRATION

Descriptive Note:

Corporate Author:

AEROSPACE CORP SAN BERNARDINO CA

Personal Author(s):

• Smith, Frank A.
• Benedetti, F. J.

Report Date:

1965-09-01

Pagination or Media Count:

32.0

Abstract:

The underlying problem in the prediction of re-entry vibrations is the fundamental question regarding the effectiveness of the boundary layer noise to produce structural vibrations, particularly during flight at velocities up to Mach 20. Although the pressure fluctuations in the boundary layer are thought to be larger during the re-entry period than boost, this effect is cancelled, in part, by the increased velocities which distributes the energy over a much broader frequency bandwidth up to 100 kc. Thus, for the frequency range of interest up to 2000 cps, the predicted vibration criteria may vary by as much as ten decibels between any two analysts, depending upon how these factors are treated. This paper presents, in nondimensional form, recent broadband vibration data which indicates a trend toward higher vibration levels during the re-entry period as compared to the boost period. The data are as yet insufficient both in quantity and quality to accurately assess the effect on vibration levels of all flight parameters such as effects due to various ablative materials however cursory checks of these data show that they tend to follow the dynamic pressure characteristics.

Descriptors:

• *REENTRY VEHICLES
• VIBRATION
• ATMOSPHERE ENTRY
• BOUNDARY LAYER
• LAUNCH VEHICLES
• ACOUSTICS
• NOISE
• BOUNDARY LAYER TRANSITION
• LOW FREQUENCY
• ABLATION
• BROADBAND

Subject Categories:

• Guided Missile Reentry Vehicles

Distribution Statement:

APPROVED FOR PUBLIC RELEASE