• Scientific/Engineering
  • Capabilities
    • Artificial Intelligence
    • AI Projects
    • Structural Dynamics and Acoustics
    • SDA Projects
    • Planning and Scheduling
    • Probabilistic Reasoning
  • Contracts
    • Acquisition Planning
    • Blast/ESET
    • CES
    • ECAT
    • Command and Control
    • CORRDBMS and AIRS
    • Logic Model
    • Digital Library Search Methods
    • 2nd Order Uncertainty
    • Life Signs Monitoring

Structural Dynamics and Acoustics

GCAS's experience spans many years of aerospace product development in structural dynamics and acoustic analysis, testing and noise control. Specific project experience includes:

• Prediction of the interior noise of aircraft due to wing mounted propeller excitation
• Jet exhaust noise prediction using numerical methods from turbulence models as well as semi empirical methods based on test data
• Jet exhaust noise measurements including noise source surveys of plume and correlation with turbulence measurements
• Jet exhaust nozzle and suppressor design from predictions and substantiation of levels from measurements
• Propeller, fan, compressor and turbine noise predictions from the unsteady aerodynamic field established on the airfoil by upstream wakes, turbulent inflow, or the shock field generated at supersonic speeds
• Acoustic testing of fans, propellers, compressors and turbines for sound level correlation with the unsteady flow field
• Semi empirical prediction models of combustion noise from experiments
• The sound field generated within the combustor during liquid rocket combustion instability
• Noise path discrimination and identification
• Noise generated in turbulent boundary layers and wakes, including the effect of surface roughness on self noise
• Structural borne noise, such as from vibration generated by engines, pumps and equipment through the structure to cavities and panels
• Prediction of low level noise from motors, pumps, electrical equipment, and hydraulic systems
• Impact noise prediction and measurement
• Acoustic treatment design and testing
• Flow noise in pipes and ducts
• Prediction methods for the flow induced noise over submarines
• Effectiveness of submarine hull coating on echo reduction
• Acoustic fluid structure interaction for predicting the interior noise in aircraft fuselages, automobile interiors and submarine hulls
• Noise radiation pattern prediction and measurement from structural surfaces
• Acoustic reverberation room and anechoic chamber design and check out
• Accuracy and precision of acoustic measurements
• Reverberation room measurements of satellite panels, electronic packages and other sensitive equipment
• Correlation of reverberation room environment to actual flight environment
• General noise surveys of communities, factories, airports, etc. to meet FAA, OSHA and other governmental noise regulations
• Design of control rooms, computer rooms, work areas, etc., for low noise
• Correlation and coherence analysis of acoustic and other time series analysis
• Acoustic fatigue analysis of structures including the effect of the dynamics of the structure, such as with panels
• Sound propagation effects, including air attenuation and density gradients
• Effect of surface reflections on measured sound levels
• Sound enclosure design
• Design of specialized noise measurement equipment, such as probe stems, directional arrays and mirrors

The following describes some of the contracts we have had in Structural Dynamics and Acoustics: In the area of dynamic testing GCAS has three retail test systems products: