Analysis of the aerodynamic forces acting on baseball pitches from major league games reveals a large variance in the measured coefficients of lift and drag. We have examined possible explanations for this effect and found that, while uncertainties introduced by measurement error and the method of reporting major league pitch trajectories do explain some of the spread, the reasons for the large...

We have studied oscillation of a pendulum in water using spherical bobs. By measuring the loss in potential energy, we estimate the drag coefficient on the sphere and compare to data from liquid-helium experiments. The drag coefficients compare very favorably illustrating the true scaling behavior of this phenomenon. We also studied the decay of amplitude of the pendulum over time. As observed ...

In this paper, a thorough 2D unsteady computational fluid dynamic analysis was performed on pitching airfoil to properly comprehend the stall and aerodynamic forces. The software ANSYS Fluent used solve Reynolds-averaged Navier–Stokes equations. Low Reynolds number flows were modeled using k-ω shear stress transport turbulence model. Aerodynamic forces, flow structures, separation delay angles ...

• Obtain predictive models for the drag coefficient of a sphere using symbolic regression. The depends on logarithmic terms Reynolds number. have higher extrapolation range than power-based models. can predict crisis at high numbers. proper behaviour low number regime. At beginning second half twentieth century, Proudman and Pearson (J. Fluid. Mech.,2(3), 1956, pp.237-262) suggested that functi...

Trains with different numbers of cars running in the open air were simulated using the delayed detached-eddy simulation (DDES). The numbers of cars included in the simulation are 3, 4, 5 and 8. The aim of this study was to investigate how train length influences the boundary layer, the wake flow, the surface pressure, the aerodynamic drag and the friction drag. To certify the accuracy of the me...

Low Reynolds number aerodynamics is important for various applications including micro-aerial vehicles, sailplanes, leading edge control devices, high-altitude unmanned vehicles, wind turbines and propellers. These flows are generally characterized by the presence of laminar separation bubbles. These bubbles are generally unsteady and have a significant effect on the overall resulting aerodynam...