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The advent of fossil-fuel engines has provided aeronautical engineers with a ten-fold to hundred-fold increase in power-to-gross-weight ratios over the ratios available for biologically-powered flight creations, such as birds and human-powered aircraft. The tremendous achievements of engine-powered aircraft over the past eight decades have tended to obscure the fact that numerous flight problems had...
Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1–10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance of the low characteristic...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.