Stories
167
1933
0
210
30
Briefs: Mechanical & Fluid Systems
An active-control surface modal (ACSM) device has been developed as an improved means of alleviating buffet of an aircraft. The ACSM device is a "smart" actuator system that includes an array...
Briefs: Mechanical & Fluid Systems
Uncertainty Models From Ground Vibration Testing
Structural dynamics are often an important consideration when evaluating system characteristics. A concern related to structural dynamics is the analysis of flutter for a flight vehicle. The instability associated with flutter can be quite sensitive to the structural dynamics; therefore, analysis of...
Briefs: Physical Sciences
A new method for assessing and communicating aviation in-flight icing hazards has been proposed. This methodology creates a simple numerical index for quantifying hazard severity. The index...
Briefs: Motion Control
Self-tuning impact dampers have been proposed as improved means for suppressing vibrations in the rotor blades of turbomachines (turbines and compressors). Dampers are needed because...
Briefs: Software
Program for Simulating Rotor Dynamics on Personal Computers
ARDS (Analysis of RotorDynamic Systems) is a public-domain computer program that simulates transient and steady-state dynamics of a rotary machine that can include as many as five interconnected flexible shafts. ARDS can be used to analyze the dynamics of such diverse machines as...
Briefs: Information Technology
A method to predict the onset of a limit cycle for an aeroelastic testbed has been developed. The prediction is based on wavelet processing of measurement data that have been recorded under various...
Briefs: Mechanical & Fluid Systems
The tail boom of a single-rotor helicopter is subjected to a complex flow field that includes the wakes of the main and tail rotors, the freestream, and the wake from the forward...
Briefs: Robotics, Automation & Control
An improved secondary wing system of the canard type has been invented to improve performance and increase efficiency of airplanes capable of flight at supersonic and high subsonic speeds. Canards, including small...
Briefs: Mechanical & Fluid Systems
Insulating tiles with interlocking shaped gaps have been developed for use in protecting the leading edges of the wings of aerospacecraft against excessive heating during hypersonic flight...
Briefs: Information Technology
The numerical speed of sound is a variable that is used in the numerical solution of flows from low to high speeds. The numerical speed of sound is an effective speed of sound associated with Mach numbers used in the...
Briefs: Information Technology
A recently developed method of parameterizing complex shapes that one seeks to optimize differs from prior such methods in two major respects: (1) instead of entirely...
Briefs: Mechanical & Fluid Systems
Mathematical models to approximate the dynamics of aircraft are often generated by considering aircraft structures to be rigid bodies. These models may be unsuitable for evaluating the...
Briefs: Mechanical & Fluid Systems
A continuing program of research is directed toward the development of crashworthy composite-material fuselages for small aircraft. These fuselages are required not only to withstand...
Briefs: Mechanical & Fluid Systems
Computational Test Cases for a Rectangular Supercritical Wing
A report describes wind-tunnel experiments on a rectangular supercritical wing and presents test cases that have been selected from the archived sets of experimental data for comparison with computational fluid dynamics (CFD) predictions. In the experiments, the wing was driven in...
Briefs: Mechanical & Fluid Systems
Conservatism in Deterministic Structural Analysis
A paper discusses the excessive conservatism that has long been suspected to exist, because of the use of conventional (deterministic) safety factors, in the analysis and design of quasi-static structures. The origin of this conservatism is identified as a violation of statistical error-propagation...
Briefs: Mechanical & Fluid Systems
Experiments on Vibration and Noise in Fuselages
A paper summarizes a continuing program of vibro-acoustic testing of two aircraft fuselage structures: (1) a 12-ft (3.7-m)-long generic aluminum test-bed cylinder that contains stiffening rings and stringers and (2) the 40-ft (12.2-m)-long fuselage of a 10-passenger turboprop airplane, made of...
Briefs: Mechanical & Fluid Systems
Accelerations of One Airplane in Wake Vortices of Another
Accelerations of one airplane encountering a vortex or pair of vortices in the wake of another airplane were computed in a parametric study. The approach taken in the study was to systematically investigate the effects of progressively more nearly complete descriptions of the interaction of...
Briefs: Motion Control
An apparatus called a "pneumatic stinger" has been developed to enable a first spacecraft, operating under remote control, to grasp a second spacecraft that is in orbit or other...
Briefs: Mechanical & Fluid Systems
FoilSim is a computer program that calculates and graphically depicts information on flows of air around airfoils of various shapes. Although it is useful primarily as a teaching tool to enhance...
Briefs: Mechanical & Fluid Systems
A change in the design of the engine inlets of the T-38 airplane significantly reduces takeoff distances while increasing safety margins. Although the newer inlet design (see Figure 1) is based on well-known...
Briefs: Mechanical & Fluid Systems
Some changes in the design and construction of the leading edges of metal airplane wings have shown promise as means to suppress laminar-to-turbulent flow transitions. The significance...
Briefs: Mechanical & Fluid Systems
Direct measurement of aircraft-engine thrust by use of strain gauges offers several advantages over traditional model-based methods of calculating thrust, provided that care is...
Briefs: Robotics, Automation & Control
An experiment consisting of flight tests on the X-31A airplane (see figure) has demonstrated the ability to use thrust vectoring to replace the functions of stabilization and turn...
Briefs: Manned Systems
It is not necessary to allocate valuable forebody volume to strake-deployment mechanisms.
Briefs: Photonics/Optics
The Boeing Company has developed an overhead camera system that can automatically spot small pieces of debris on a work surface that might otherwise go unnoticed. The system automatically analyzes inputs...
Briefs: Physical Sciences
An imaging spectroscopic technique is undergoing development for use in remote detection of ice and mapping of the thickness of ice on aircraft surfaces. The technique is based on the...
Briefs: Robotics, Automation & Control
An improved hybrid thermal/mechanical system has been developed to protect airplane wings and other airfoils against the accretion of ice, which degrades aerodynamic performance. The...
Briefs: Physical Sciences
Aircraft-Skin-Rivet Thermocouple
The aircraft-skin-rivet thermocouple is designed for measuring the temperature on the outer surface of an airplane wing under icing conditions. More specifically, its design was motivated by the need to measure the temperature near 32 °F (0 °C) on an aluminum wing skin, with an error of no more than 1 °F (0.6...
Briefs: Mechanical & Fluid Systems
Rigid, guyed masts of a proposed type for supporting meteorological instruments would be designed to withstand considerably stronger winds than those conventionally used. The proposed fairings...
Top Stories
Blog: Software
Going for Gold in Winter Olympic Curling
Blog: Energy
Beyond Lithium: The Rise of Calcium-Ion Energy Storage
Blog: Electronics & Computers
The Kitchen Tech Hack Aiming to Revolutionize 3D Printing
Blog: Materials
A Shield for the Next Generation: Lithium Batteries Get a Major Upgrade
Blog: Energy
Batteries that Can Withstand the Cold
Q&A: Physical Sciences
Webcasts
Webinars: Mechanical & Fluid Systems
The Over-Engineering Trap: Aligning Custom Equipment Specs with Operational...
Webinars: Communications
Where Time and Frequency Converge: Multi-Channel RF Analysis for Radar and...
Webinars: Software
Driving Reliability: Simulation Driven EMI Techniques for Modern Vehicle...
Editorial Webinars: Software
Smarter Aerospace Manufacturing & Design with Digital Twins and Agentic AI
Summits: AR/AI
2026 Battery & Electrification Summit (Online)
Podcasts: Information Technology
Arm’s Agentic AI CPU: Engineering the Next Generation of AI Data Centers
