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Chp 3. Filtered eqs And Turbulence. Why filter eqs?. The governing eqs permit motions on all scales: Planetary scales: 1000’s of km Cb’s: 10km Turbulent eddies:100’s of m Viscous eddies: 1mm A numerical model cannot cover the entire range of scales. What is turbulence?.
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Chp 3 Filtered eqs And Turbulence
Why filter eqs? • The governing eqs permit motions on all scales: • Planetary scales: 1000’s of km • Cb’s: 10km • Turbulent eddies:100’s of m • Viscous eddies: 1mm A numerical model cannot cover the entire range of scales
What is turbulence? • Difficult to define but you know it when you see it or feel it. • Turbulent flows have large Reynold’s numbers
Fig. 3.1. Photograph of a cumulonimbus cloud showing turbulent eddies of many scales.