TGS2014: International Short Course
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New Theory on Turbulence Generation and Sustenance in a Boundary Layer


Part I New Theory on Turbulence Generation:
1. Governing equation and DNS code
2.
Orr-Sommerfeld equation and its solution
3.
Vortex structure visualization by lambda 2 and vortex filaments
4.
Spanwise vortex formation and role of linear unstable modes (cannot form vortex but pushing vorticity up from the wall surface)
5.
Shear layer stability analysis and inflection points (Shear layer instability is the mother of turbulence)
6.
Lambda vortex root formation (Lambda vortex is not a vortex tube) by 3-D unstable modes which is extremely unstable
7.
Ring like vortex formation which is not part of Lambda vortex (There is no such a process that the Lambda vortex self-deforms to hairpin vortex; lambda roots and vortex rings are developed separately by different mechanisms)
8.
Mechanism of multiple vortex ring formation (There is no vortex breakdown and reconnection) ¨C all are formed by shear layer instability which is generated by momentum deficit through vortex ejection.
9.
U-shaped vortex (Not secondary but tertiary)
10.
Sweeps, ejections, positive and negative spikes, and high shear layers in turbulent flow
11.
Small length scale generation ( Not by vortex breakdown, but all are generated by shear layer instability which is formed by positive and negative spikes)
12.
Energy transfer paths from larger vortex to smaller vortex (Not by vortex breakdown but by vortex ring sweeps)
13.
Flow Chaos (Not only by background noises but mainly by instability of multiple vortex package structure)
14.
Richardson eddy cascade revisit (There is no such a cascade)
15.
Kolmogorov hypothesis revisit (There is no vortex breakdown and there is no energy passing through vortex breakdown. There is no proof of existence of Kolmogorov small scale)
16.
Flow transition and turbulent flow control (Control the shear layers)
17.
Intermittence revisit (There is no intermittence in turbulence)
18.
Turbulence model revisit (Model the vortex packages and relative motion between packages)
19.
No matter how to define ˇ°vortexˇ±, small vortices (turbulence) cannot be generated by ˇ°vortex breakdownˇ±. All small vortices are generated by shear layer without exception. In other words, ˇ°shear layer instability is the mother of turbulenceˇ±
20.
Existing ˇ°vortex breakdownˇ± graphics were obtained by faked visualization by using improper lambda2 values.

Part II Large Eddy Simulation for Supersonic Micro Vortex Generator (MVG)
1.
Governing equation, grid generation and high order schemes
2.
Turbulent inflow generation
3.
Code validation by experiment conducted by UTA and Delft
4.
Momentum deficit generation by MVG
5.
K-H instability and vortex ring formation
6.
Origin of the ring-like vortices and their evolution
7.
Investigation of the supersonic MVG wake
8.
Vortex-ring and shock interaction
9.
Mechanism of reduction of shock induced boundary layer separation
10.
Pressure fluctuation spectrum analysis

Please check the web page at http://www.uta.edu/math/cnsm/tgs2014 or Contact caixiac@uta.edu if you are interested.

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