UNLABELLED A "negative interaction" between step length and step rate refers to an increase in one factor resulting in a decrease in the other. PURPOSES There were three main purposes: a) to investigate the relative influence of the determinants of step length and step rate, b) to determine the sources of negative interaction between step length and step rate, and c) to investigate the effect...

Historically, powered lift takeoff analysis has been prohibitively expensive for use in preliminary design. For powered lift, the coupling of aircraft systems invalidates traditional simplistic methods often used in early aircraft sizing. This research creates a tool that will automate the process of takeoff and balanced field length calculations for a circulation control wing aircraft. The pro...

This work provides a feasible solution to the shipborne short landing problem for thrust-vectoring V/STOL vehicles. The takeoff and rolling vertical strategy was designed in this work. First, design reference established by flying performance mission requirements, including performance, deceleration trajectory stability, velocity conversion corridor, using attainable equilibrium set methods bas...

Currently, several solar-powered unmanned aerial vehicles (UAVs) have achieved 24 h uninterrupted cruise. However, models that can cruise for weeks or even months without interruption are in the minority. The technological progress requires improvement of subsystems and also depends on accurate planning flight profile power spectrum a long working cycle. Combined with test data obtained during ...

Flight performance seems to change systematically with body size: small animals can hover and fly over a wide range of speeds, but large birds taxi for takeoff and then fly over a narrow speed range. The traditional explanation for this is that the mass-specific power required for flight varies with speed according to a U-shaped curve, and it also scales between m° and m/, where m is body mass....

In the high frequency regime, the geometrical-optics approximation for the Helmholtz equation with a point source results in an eikonal equation for traveltime and a transport equation for amplitude. Because the point-source traveltime field has an upwind singularity at the source point, all formally high-order finite-difference eikonal solvers exhibit first-order convergence and relatively lar...

The research effort is a Reynolds-Averaged Navier-Stokes (RANS) investigation that looks at the flow-field and performance of a bypass ratio 8 nozzle with an external wedgeshaped noise suppressor, simulating the exhaust of a turbofan engine at takeoff conditions. Peak turbulence was reduced by the wedge on the side opposite the deflector, and it was increased in the initial region of the jet be...