The higher pollutant level in non premixed combustion and safety issues pertaining to can be counteracted by partially-premixed mode of combustion. partially flames (PPF) exhibit the benefits both flames. PPF enhances complete leading reduced soot formation hence lower emission. However, equivalence ratio plays an important role stability such This paper reports experimental investigation on fl...

A finite element flow solver based on unstructured grids is employed for studying the aerodynamic characteristics of Micro Air Vehicles. Inviscid and viscous flow simulations were performed for two different Micro Air Vehicles developed at NRL. Lift and drag force variations were computed for a range of flow angles and control surface angles. The Baldwin-Lomax turbulence model was employed for ...

For centuries, mankind has been fascinated by V-formation flight in birds. Back in AD 79, Pliny the Elder noted that flocks of geese flew ‘like fast galleys, cleaving the air more easily than if they drove at it with a straight front’, and since then, numerous ideas have been proposed to explain the function of the V-shaped flocks that are a such a familiar sight. Many of these explanations oft...

A flight-dynamics oriented simulation model of a flapping-wing Micro Air Vehicle (MAV) has been developed. This concept is based on flapping flight performed in nature by insects or hummingbirds. An optimization of the flapping kinematics of the wing has been led, in order to maximize the mean lift and thus the payload. A neural network has been designed to reproduce the function shape of the w...

Cl = section lift coefficient c = local chord length D = fading-memory constant G = nondimensional circulation l = section lift force/length m = number of points used in sine series expansion of circulation function N = consecutive iterations convergence parameter r = perpendicular distance from vortex tol = iteration relative tolerance of conversion U1 = freestream velocity magnitude w = downw...

The object of this study is a disc valve. In particular, the transient behaviour of the valve is studied as the valve moves from being fully closed and sealed to being fully open with steady-state flow of air established. The steady-state behaviour is well researched, the transient behaviour less so. A common assumption in valve design is that transient valve behaviour can be accurately represe...

There are three common methods for calculating the lift generated by a flying animal based on the measured airflow in the wake. However, these methods might not be accurate according to computational and robot-based studies of flapping wings. Here we test this hypothesis for the first time for a slowly flying Pacific parrotlet in still air using stereo particle image velocimetry recorded at 100...

Batch and continuous production of the extracellular heme glycoprotein chloroperoxidase (CPO) was studied with an airlift fermentor. We induced Caldariomyces fumago CMI 89362 to form pellets by transferring a small inoculum volume in preculture prior to growth in a 1-liter fermentor. Continuous replacement of the fructose-salts medium (dilution rate, 0.008 h) supported continuous CPO formation ...

As they descend, the autorotating seeds of maples and some other trees generate unexpectedly high lift, but how they attain this elevated performance is unknown. To elucidate the mechanisms responsible, we measured the three-dimensional flow around dynamically scaled models of maple and hornbeam seeds. Our results indicate that these seeds attain high lift by generating a stable leading-edge vo...