The airfoil equation is considered over two disjoint intervals. Assuming the distance between the intervals is small an approximate solution is found and relationships between this approximation and the solution of the classical airfoil equation are obtained. Numerical results show the convergence of the solution of the original problem to the approximation. Polynomial solutions for an approxim...

Previous theories and empirical formulas for the lift of flat planing surfaces are reviewed, and the resemblance of the planing surface to the airfoil noted. A simple expression, which converges to the correct limits for exactly known cases, is assumed for the ratio of planing to airfoil lift, and the planing lift is then estimated by using airfoil experimental data. The resulting calculated va...

Detailed knowledge of local external heat transfer around a turbine airfoil is critical for an accurate prediction of metal temperature and component life. This paper discusses the results of measurements of the local gas side heat transfer coefficient distribution which were performed in an annular gas turbine vane hot-cascade test facility and provides comparisons with analytical predictions....

The extremely thick blade root airfoils of the modern megawatt-scale wind turbines are prone to having sharp stall characteristics with associated unsteady aerodynamic blade loading and fatigue. With current technology designs reaching 45% thickness, these thick airfoils are incapable of producing high lift, and as a consequence they are aerodynamically and structurally sub-optimal. A computati...

In this paper, optimal airfoil shapes are found through manipulation of the velocity distribution by a genetic algorithm. The airfoil geometries are generated by an inverse method from velocity distribution parameters, and a viscous-flow analysis code is used to determine proper fitness values for candidate airfoils based on preset performance criteria. The method is compared with the more trad...

We explore the presence of torques at the inner edges of geometrically-thin black hole accretion disks using 3-dimensional magnetohydrodynamic (MHD) simulations in a pseudo-Newtonian potential. By varying the saturation level of the magnetorotational instability that leads to angular momentum transport, we show that the dynamics of gas inside the radius of marginal stability varies depending up...

OBJECTIVE The purpose of this study was to clarify the pathogenesis of plunging ranulas in regard of the pathway of lesion propagation using CT scans. MATERIALS AND METHODS We retrospectively reviewed CT scans of 41 patients with plunging ranula. We divided plunging ranulas into two types: type 1 was defined as those directly passing through a defect of the mylohyoid muscle with the presence ...

More than 100 research articles have referred to an experimental study by Feldkamp (1987) on the California sea lion, which mentions that its body resembles a symmetric airfoil, NACA 66018. We believe that perhaps an oversimplification has been made in this comparison. This conclusion may be arrived at by shifting the leading and trailing edges of the contour of the sea lion in order to move th...

More than 100 research articles have referred to an experimental study by Feldkamp (1987) on the California sea lion, which mentions that its body resembles a symmetric airfoil, NACA 66018. We believe that perhaps an oversimplification has been made in this comparison. This conclusion may be arrived at by shifting the leading and trailing edges of the contour of the sea lion in order to move th...

The capacity of rainbow trout to experience fear was assessed using an avoidance learning task. Each of 13 fish was placed individually into a two-chambered shuttle tank where it could be subjected to the putative frightening stimulus of a plunging dip net in either chamber. The fish could escape from the stimulus by swimming through a doorway to the other chamber. The fish escaped from the plu...