engine and airframe manufacturers for decades have cited the direct relationship between engine wear and high exhaust gas temperature (EGT) in recommending that operators use less than maximum takeoff thrust whenever possible. While the cost benefits of reduced-thrust takeoffs are thoroughly documented, the safety benefits are not as well understood. Thus, there is a common perception that usin...

A literature review, a datasheet review, and in-house experimental data were used to obtain a real-world comparison between bio-mimetic pectoral fins and traditional propeller-based thrusters. Only power consumption, forward thrust, and propulsive efficiency are compared. Scaling trends for both propulsion forms are discussed. Traditional thrusters are determined to be more efficient than curre...

In Sepioteuthis lessoniana, the oval squid, ontogenetic changes in the kinematics of the mantle during escape-jet locomotion imply a decline in the relative mass flux of the escape jet and may affect the peak weight-specific thrust of the escape jet. To examine the relationship between ontogenetic changes in the kinematics of the mantle and the thrust generated during the escape jet, we simulta...

The combination of detailed topographic leveling on the southwest segment of the El Asnam thrust fault with existing seismic and geologic data implies that the geometry of this fault involves shallow dipping flats and steep ramps. The fault appears to be growing along strike toward the southwest end, where the main shock initiated in 1980. From a depth of about 10 km, the main thrust appears to...

It is well known that each thruster on the SPHERE produces slightly different thrust and behaves differently (see [Chen] and [Berkovitz]). Some methods were developed by [Chen] to compensate for the difference in thrust between thrusters and improve the open-loop performance of the SPHERE, but they were yet to be demonstrated. An experiment was performed onboard NASA’s KC-135, during microgravi...

In this paper, the impacts of the uncertainty of fuel heating value as well as the burner efficiency on performance functions of a turbofan engine are studied. The mean value and variance curves for thrust, thrust specific fuel consumption as well as propulsive, thermal and overall efficiencies are drawn and analyzed, considering the aforementioned uncertainties based on various Mach numbers at...

Traditional statements of the celebrated Kalman filter algorithm focus on the estimation of state, but not the output. For any outputs, measured or auxiliary, it is usually assumed that the posterior state estimates and known inputs are enough to generate the minimum variance output estimate, given by yn|n = Cxn|n + Dun. Same equation is implemented in most popular control design toolboxes. It ...

Abstract The thrust producing performance and efficiency of an SD8020 oscillating foil with a symmetrical saw-tooth angle of attack pitching profile was studied through force and torque measurements, as well as dye flow visualization, in the water tunnel at low Reynolds number of 13,000-16,000. The propulsive efficiency and thrust coefficient of the pitching foil were determined as a function o...