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مکانیک::
هیدرودینامیک، هیدرودینامیک
He flew bombing and reconnaissance raids, calculated the first bombardment tables, organized the first Russian air reconnaissance service and the factory of navigational devices (in Moscow, with Joukovsky's support), all the while publishing scientific papers on hydrodynamics and atmospheric physics.
He stressed that his goal was pragmatic (predictive meteorology) and that only a consistent theory of turbulence can pave the way for dynamical meteorology: "Instruments give us mean values while hydrodynamic equations are applied to the values at a given moment".
To de- scribe turbulence at large Reynolds number Re, one needs to face eventually the third moment and account for the nonlinearity of hydrodynamics.
Such an approximation is valid only for weakly nonlinear systems such as the weak wave turbulence described in Section 6.4 below; for hydrodynamic turbulence it is a semi-empirical approximation which was extensively used for the next forty years.
This book firmly set hydrodynamics as part of physics.،CF/IL/axial motions, structural and geometric nonlinearities and nonlinearities associated with the hydrodynamic forces caused by uniform and linearly sheared flows.
Furthermore, significance of structural and hydrodynamic nonlinearities will be examined numerically and analytically and the results of these analyses will be applied for extracting two-dimensional hydrodynamic force coefficients.
* In Chapter 5, analytical closed-form expressions are derived for the extraction of hydrodynamic coefficients and maximum responses from the 2DOF VIV, the system phase relationships of wake and cylinder motions and various maps of hydrodynamic coefficients are presented, the analytically-obtained contour plots of maximum cross-flow/in-line responses are highlighted and a shortcoming of using a linear structural oscillator and applying a constant empirical coefficient to the wake oscillator is underlined.
The numerical and analytical analyses performed in this thesis will illustrate the importance of structural and hydrodynamic nonlinearities for accurate VIV predictions and will open a new chapter in the field of phenomenological VIV models.
Fluctuating and mean hydrodynamic coefficients
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