Wind tunnel test on a 1/4.622 Froude scale, hingeless rotor, tilt rotor model, volume 1

Wing tunnel test data on a 1/4.622 Froude scale, hingeless rotor, tilt rotor mode are reported for all potential flight conditions through hover and a wide envelope of transitions. A mathematical model was used to describe the rotor system in real time simulation by means of regression analyses. Details of the model, test program and data system are provided together with four data files for hover and transition

The investigation of flame spreading over the surface of igniting solid propellants Final summary report

Flame spreading over surface of igniting solid propellants in different gas mixtures at various pressure

Solid state switch provides high input-to-output isolation

Switch uses a combination of N-channel and P-channel Metal Oxide Semiconductor Field Effect Transistors /MOSFET/ to obtain a normally open switch with no power applied. Series-shunt-series MOSFET switching achieves high input-output isolation

Adhesive coating eliminated in new honeycomb-core fabrication process

Technique eliminates use of silicone-based adhesive material as bonding medium. Adhesive requires precise time-temperature cure. Prepreg resin is used as bonding medium, and each layer is laminated together to form honeycomb billet. Process can be used in any application where nonmetallic honeycomb core is being fabricated

Swashplate feedback control for tilt-rotor aircraft

Changes in angle of attack in system were sensed indirectly by gages which responded to strains induced in wing structure. Output signals were amplified, filtered, and used to activate swashplate actuators. System provided significant reduction in blade loads and desirable changes in hub forces and moments

Allocating Awards Across Noncomparable Categories

Suppose an agency awards a …xed number of prizes to applicants in different categories such that the applicant-to-winner ratio is constant by category. It is demonstrated in a simple theoretical model that the number of awards in a category will typically be positively related to the degree of applicant uncertainty. The theoretical …ndings are related to awards data from the Social Sciences and Humanities Research Council of Canada doctoral fellowship competition.

Fluent temporal logic for discrete-time event-based models

Fluent model checking is an automated technique for verifying that an event-based operational model satisfies some state-based declarative properties. The link between the event-based and state-based formalisms is defined through fluents which are state predicates whose value are determined by the occurrences of initiating and terminating events that make the fluents values become true or false, respectively. The existing fluent temporal logic is convenient for reasoning about untimed event-based models but difficult to use for timed models. The paper extends fluent temporal logic with temporal operators for modelling timed properties of discrete-time event-based models. It presents two approaches that differ on whether the properties model the system state after the occurrence of each event or at a fixed time rate. Model checking of timed properties is made possible by translating them into the existing untimed framework. Copyright 2005 ACM

Flame Spreading over the Surface of Double Base Propellants at High Pressure Annual Report

Flame spreading over igniting surface of double base propellants in high pressure quiescent environmen

Conceptual design study of a 1985 commercial STOL tilt rotor transport

Results of conceptual engineering design studies of a STOL tilt rotor commercial aircraft for the 1985 time frame are presented. The details of aircraft size, performance, flying qualities, noise, and cost are included. The savings in terms of fuel economy resulting from STOL operations compared with VTOL vehicles are determined