Saturday, September 19, 2009

Refuel

gripen-in-flight-refueling.jpg image by frontierindia

Sonic Boom

 

The change in pressure as the plane outruns all of the pressure and sound waves in front of it is heard on the ground as an explosion or sonic boom.

Every so often, just the right combination of conditions and events occur to create an unbelievable event -- in this case an F-18 passing through the sound barrier. Not only were the water vapor, density and temperature just right, but there just happened to be a camera in the vicinity to capture the moment. The F-18 is actually in transonic flight, with normal shock waves emanating from behind the canopy and across the wings and fuselage. The condition will last for only an instant, and once supersonic flow exists completely around the aircraft, sharp-angled sonic cones replace the normal shock waves. The odds of getting a shot like this are staggering. I like it.

Transonic F-14D Tomcat Fighter Jet With Its Prandtl-Glauert Cloud on July 28, 2006, USS Theodore Roosevelt (CVN 71) Atlantic Ocean. The United States Navy F-14D Tomcat figher jet is 'aircraft number 100, assigned to the Tomcatters of Fighter Squadron Three One (VF-31),' and is making a 'near supersonic fly-by above the flight deck of USS Theodore Roosevelt (CVN 71).' Source for the quotes: 'F-14 near supersonic fly-by' at <http://www.navy.mil/view_single.asp?id=37555>). Photo Credit: Mass Communication Specialist 3rd Class Nathan Laird, Navy NewsStand - Eye on the Fleet Photo Gallery (http://www.news.navy.mil/view_photos.asp, 060728-N-7241L-026), United States Navy (USN, http://www.navy.mil), United States Department of Defense (DoD, http://www.DefenseLink.mil or http://www.dod.gov), Government of the United States of America (USA). This picture (photograph) is included in 'ChamorroBible.org: Prandtl-Glauert Condensation Clouds, 1st Collection', ChamorroBible.org, Manguaguan na Palabran Si Yuus -- God's Precious Words of August 17, 2004.

1. United States Fighter Jet From the 'Black Knights' of the Marine Fighter Attack Squadron Three One Four (VMFA-314). January 29, 2004, Pacific Ocean. Reaching the sound barrier, breaking the sound barrier: Flying at transonic speeds (flying transonically) -- speeds varying near and at the speed of sound (supersonic) -- can generate impressive condensation clouds caused by the Prandtl-Glauert Singularity. For a scientific explanation, see Professor M. S. Cramer's Gallery of Fluid Mechanics, Prandtl-Glauert Singularity at <http://www.GalleryOfFluidMechanics.com/conden/pg_sing.htm>; and Foundations of Fluid Mechanics, Navier-Stokes Equations Potential Flows: Prandtl-Glauert Similarity Laws at <http://www.Navier-Stokes.net/nspfsim.htm>. Photo Credit: Photographer's Mate Airman Chris M. Valdez, Navy NewsStand - Eye on the Fleet Photo Gallery (http://www.news.navy.mil/view_photos.asp, 040129-N-0905V-024), United States Navy (USN, http://www.navy.mil), United States Department of Defense (DoD, http://www.DefenseLink.mil or http://www.dod.gov), Government of the United States of America (USA).