Aeronautics

Supersonic Unmanned Aerial Vehicles Close To Becoming Reality

January 30, 2013 in Aeronautics, Aerospace, Case Studies, Tecplot Chorus Case Studies

Overcoming the curse of dimensionality in hypersonic design

May 19, 2012 in Aeronautics, Aerospace, Research, Tecplot Chorus Case Studies

Selected image view with Tecplot Chorus

Continuum-Dynamics, Inc. uses Tecplot 360 to develop first commercial ship air wake database for U.S. Navy helicopter flight simulators

March 27, 2011 in Aeronautics, Case Studies

helicopter_landing_on-ship

NASA CFD software helps quiet the skies

March 16, 2003 in Aeronautics, Aerospace, Case Studies

Figure 1: Noise sources in a jet plume visualized with Tecplot. The jet plume originates from a bypass ratio (BPR) typical of a transport aircraft. Noise sources are shown in a 12,500 Hz frequency band (sub-scale) with the observer at 88 degrees to the inlet. The data set has about 35 variables at 17 million cells.

Bypass ratio relates the size of the fan stream to the size of the core stream. The inner core stream consists of hot, high velocity gas passed through the jet engine combustor. The outer fan stream consists of cooler, lower velocity air pulled into the engine via the fan.

There are numerous frequencies of noise. The human ear is sensitive to noise from 20Hz - 20kHz. When full scale (9 times larger), the noise shown in the plot would be about 1400Hz, in the range of noise that annoys people.

The observer (or a microphone) can be at numerous angles relative to the jet engine. The inlet angle is measured from the front of the engine. Zero would be pointing ahead, 90 degrees to the side, and 180 degrees points downstream in the direction of the jet exhaust.