The Earth angle moment balance, low-frequency atmospheric processes and radiowaveguides: ii. application of an advanced non-stationary theory for different forms of atmosphere circulation

In the paper we present the results of application of a new advanced non-stationary theory of global mechanisms in atmospheric low-frequency processes, the balance of the angular momentum of the Earth, teleconnection effects and atmospheric radio waveguides, for the Pacific ocean region for different forms of the atmosphere circulation. The theory is realized and implemented into Microsystem Technology "GeoMath" and focused on the discovery and testing of new predictors for long-term and very long-forecasts of low-frequency atmospheric processes. The PC experiments have demonstrated an effectiveness of a new advanced theory in application to modeling balance of angular momentum, the atmospheric moisture turnover in relation to the genesis of tropospheric radio waveguides and succession processes of atmospheric circulation forms (teleconnection, front-genesis) in order to develop new practical sensors in long-term forecasting and modeling of low-frequency atmospheric processes. It is determined a link of tropospheric waveguide with atmospheric moisture circulation and, accordingly, with the shape of the atmospheric circulation over the position of the front sections of (atmospheric fronts as the main drives moisture). Atmospheric moisture cycle is linked with such typical low-frequency process as the angular momentum balance; the latter accounts violation of the atmosphere rotating balance with the Earth.

Experimental Investigation of Airfoil Subject to Harmonic Translatory Motions

This paper concerns an experimental investigation of a NACA 0015 airfoil subject to harmonic one-degree-of-freedom translatory motion. Specifically, unsteady pressure distributions were measured at a range of incidences and movement directions at reduced frequencies matching real life conditions for the lead-lag motion of wind turbine rotors. From the experimental results, hysteresis loops and aerodynamic damping were computed and compared to results from linear quasi-stationary theory and unsteady potential flow theory. The maximum negative aerodynamic damping was found to take place at moderate stall and an incidence of about 15°, at a movement direction close to the chordwise direction. Comparison with unsteady potential flow theory showed excellent agreement with the experimental data for incidences up to 5°. Linear quasi-stationary theory failed to reproduce the overall features of the aerodynamic damping for incidences above 12°.

Numerical Simulations of Jets from Accretion Disks

Hydromagnetic disk winds have great potential as a general theory for the production and collimation of astrophysical jets in both protostellar and black hole environments. We first review the analytic stationary theory of these outflows as well as recent numerical simulations of MHD disk winds. We then focus on simulations that we have done on winds from magnetized disks using the ZEUS 2-D code of Stone and Norman. We treat the Keplerian disk as a fixed platform throughout the simulations. We show that both stationary and episodic, jet-like outflows are driven from disks depending upon their magnetic structure and mass loss rates.