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...

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...

An investigation into in-cylinder swirl and tumble flow characteristics with reduced maximum valve lifts (MVL) is presented. The experimental work was conducted in the modified four-valve optical spark-ignition (SI) test engine with three different MVL. Particle image velocimetry (PIV) was employed for measuring in-cylinder air motion and measurement results were analyzed for examining flow fie...

Approximately 2,000 zero-lift, double-theodolite pilot balloon observations made at Oak Ridge, Tenn., are analyzed in order to study low level air trajectories over hilly terrain. Paths of air parcels are found to fall into characteristic groups, depending on wind speed and stability conditions. Eddy patterns for these groups are determined, and these are found to resemble similar patterns dete...

M. K. Popoviæ, C. Wulfes, and R. K. Bajpai Department of Biotechnology, FB-V, Technische Fachhochschule – Berlin, Seestraße 64, 13347 Berlin, Germany; Tel: 49 30 45043906; Fax: 49 30 45043959; Email: [email protected] *Department of Chemical Engineering, University of Louisiana – Lafayette, PO Box 44130, Lafayette, LA 70504, USA: Tel: 1 337 4825910; Fax: 1 337 482 1220; Email: bajpair@louis...

Configurations derived from classical concepts of waverider and Busemann biplane have great potential of use in aerodynamic design of highspeed vehicles with air-breathing jet engines due to their ability to provide both high lift-to drag ratio and intense preliminary compression of the flow before air intakes. The issues of conceptual design of highspeed vehicles based on the use of waverider ...

−Bacterial cellulose (BC) was produced by Acetobacter xylinum KJ1 in a modified airlift-type bubble column bioreactor, which had a low shear stress and high oxygen transfer rate (kLa). Saccharified food wastes (SFW) were used as the BC production medium due to its low cost. An aeration rate of 1.2 vvm (6 L/min) was tentatively determined as the optimal aeration condition in a 10 L spherical typ...