Oscillating hydrofoils were installed in a water tunnel as surrogate model for hydrokinetic cross-flow tidal turbine, enabling the study of effect flexible blades on performance those devices with high ecological potential. The focuses single tip-speed ratio (equal to 2), key non-dimensional parameter describing operating point, and solidity 1.5), quantifying robustness turbine shape. Both para...

Bidirectional cargo transport by molecular motors in cells is a complex phenomenon in which the cargo (usually a vesicle) alternately moves in retrograde and anterograde directions. In this case, teams of oppositely pulling motors (e.g., kinesin and dynein) bind to the cargo, simultaneously, and 'coordinate' their activity such that the motion consists of spells of positively and negatively dir...

Wind tunnel experiments have shown that bumps on the leading edge of model humpback whale flippers cause them to "stall" (i.e., lose lift dramatically) more gradually and at a higher angle of attack. Here we develop an aerodynamic model which explains the observed increase in stall angle. The model predicts that as the amplitude of the bumps is increased, the lift curve flattens out, leading to...

Wind tunnel experiments were conducted to understand boundary layer separation control on airfoils. The objective of this research was to better implement flow control strategies with single dielectric barrier discharge (SDBD) plasma actuator designs for airfoils that exhibit both leading and trailing edge stall characteristics at realistic flight speeds and Reynolds numbers. The NASA energy ef...

Statically scheduled machines do have a disadvantage when dealing with dynamic events, such as cache hit or miss detection. Early VLIW machines were designed without caches, to achieve predictability in memory access. However, such designs suffer in memory performance. To achieve high performance, VLIW architectures must have adequate support for using caches. A simple VLIW design might use an ...

Vertical axis wind turbine blades undergo dynamic stall due to the large 1 angle of attack variation they experience during a turbine rotation. Particle image 2 velocimetry on a pitching and surging airfoil was used to perform time resolved 3 measurements at blade Reynolds numbers near turbine operating conditions of 105. 4 These experiments were compared to simulations performed in the rotatin...

In the aero-elastic analysis of wind turbines based on blade element theory, the need to include a model of the local, two-dimensional instationary aerodynamic loads, commonly referred to as dynamic stall has become obvious in the last years. In this contribution we describe an alternative choice for such a model, based on [19]. Its derivation is governed by the flow physics, thus enabling inte...

Ribosome stalling on mRNAs can decrease protein expression. To decipher ribosome kinetics at stall sites, we induced ribosome stalling at specific codons by starving the bacterium Escherichia coli for the cognate amino acid. We measured protein synthesis rates from a reporter library of over 100 variants that encoded systematic perturbations of translation initiation rate, the number of stall s...

A multidisciplinary research effort that combines aerodynamic modeling and gain-scheduled control design for aircraft flight at post-stall conditions is described. The aerodynamic modeling uses a decambering approach for rapid prediction of post-stall aerodynamic characteristics of multiple-wing configurations using known section data. The approach is successful in bringing to light multiple so...