Abstract Although a coaxial compound helicopter can takeoff without propeller in the normal condition, distance should be as short possible for obstacle avoidance when vehicle operates confined area with heavy loads. Therefore, suitable control is required to improve performance while total power consumption no more than available power. The path predicted by applying trajectory optimisation. S...

Electronic power devices used for transportation applications (automotive and avionics) experience severe temperature variations, which promote their thermal fatigue and failure. For example, for power modules mounted on the engine of an aircraft, temperature variations range from –55°C (in the worst case of storage before takeoff) to +200°C (flight). Direct bonded copper (DBC) substrates are u...

PURPOSE To identify the effect of additional elastic force on the kinetic and kinematic characteristics, as well as the magnitude of leg stiffness, during the performance of accentuated countermovement jumps (CMJs). METHODS Fifteen trained male subjects performed 3 types of CMJ including free CMJ (FCMJ; ie, body weight), ACMJ-20, and ACMJ-30 (ie, accentuated eccentric CMJ with downward tensil...

The validity of an accelerometric system (Myotest©) for assessing vertical jump height, vertical force and power, leg stiffness and reactivity index was examined. 20 healthy males performed 3×"5 hops in place", 3×"1 squat jump" and 3× "1 countermovement jump" during 2 test-retest sessions. The variables were simultaneously assessed using an accelerometer and a force platform at a frequency of 0...

A large number of takeoff tests have been made on a Comet aircraft with the object of (a) acquiring comprehensive data on undirected takeoffs ; (b) testing a SCAT takeoff director. SCAT is explained in detail and the aircraft installation and test method described. Tests to determine ground effect on lift and on the SCAT Lift Transducer are also described. Undirected and directed takeoffs are c...

A microburst is a local, intense downdraft which induces an outburst of damaging winds near the ground which extends 4 km or less. Microbursts are of interest to researchers because of the strong, occasionally damaging surface winds they produce, and the hazardous wind patterns they create for aircraft in the landing or takeoff phases of flight. The dynamics and aircraft hazards posed by an iso...

In this paper, we propose a nonlinear transport model for an aviation network. The takeoff rate from an airport is characterized by the degree of ground congestion. Due to the effect of surface congestion, the performance of an airport deteriorates because of inefficient configurations of waiting aircraft on the ground. Using a simple transport model, we performed simulations on a United States...

This study used an optimization procedure to evaluate an 8-segment torque-driven subject-specific computer simulation model of the takeoff phase in running jumps for height. Kinetic and kinematic data were obtained on a running jump performed by an elite male high jumper. Torque generator activation timings were varied to minimize the difference between simulation and performance in terms of ki...

In the field of offshore renewable energy, impermeable plates are used as underwater lenses to amplify wave amplitude, and perforated can harness energy a power takeoff device. Within framework linear potential-flow theory, water scattering by horizontal is investigated in present study, both circular elliptical considered. The hypersingular integral equation constructed model interaction betwe...