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Air Pollution
Published in William J. Rea, Kalpana D. Patel, Air Pollution and the Electromagnetic Phenomena as Incitants, 2018
William J. Rea, Kalpana D. Patel
Air does not flow smoothly over the earth's surface, thus creating many changes, which will influence the diagnostic response of the chemically and electrically sensitive and chronic degenerative disease patient. Rather, it follows a three-dimensional movement of “turbulence,” which not only results in air movement change but also in changes in the quantity or quality of air ions (particularly positive ions) and other electric and electromagnetic phenomena. This movement is produced by thermal and mechanical turbulence. Thermal turbulence results from the atmosphere heating, while mechanical turbulence results from the movement of air past an obstruction. Thermal turbulence is dominant on clear sunny days with light winds. The effect of this turbulence is to enhance the dispersion process, which helps the chemically and electrically sensitive and chronic degenerative disease patient. In the case of mechanical turbulence, downwash from the pollution source may result in high pollution levels downstream. If the chemically sensitive or chronic degenerative disease patient lives and/or works in these types of high-pollution and turbulence areas, he/she often has many functional difficulties like aches, pains, mood swings, and energy bursts, followed by fatigue.
Aerodynamic Forces – Subsonic Flight
Published in Rose G. Davies, Aerodynamics Principles for Air Transport Pilots, 2020
which demonstrates the nature of the induced drag – it is caused by the induced downwash. Combining Equations (4.2) and (4.16), the induced drag Din over the wing is: Din=CDin12ρv2S=Fw∝πcρw2b[N]
Modeling and Interpreting the Aerodynamics
Published in Nandan K. Sinha, N. Ananthkrishnan, Advanced Flight Dynamics with Elements of Flight Control, 2017
Nandan K. Sinha, N. Ananthkrishnan
Downwash created by the flow over a lifting surface such as a wing modifies the flow-field downstream. As a result, any other surface, for example, a horizontal tail, located downstream of the wing experiences a slightly altered “free-stream” flow than seen by the wing. Since the aerodynamic forces and moments generated by a surface are dependent on the relative flow incident on that surface, the altered “free-stream” flow must be accounted for in the aerodynamic modeling of surfaces downstream of a lifting surface.
Numerical simulation of wake vortex for the flight near the ground with different boundary conditions
Published in Engineering Applications of Computational Fluid Mechanics, 2022
Zeyu Zhang, Dong Li, Jinxin Zhou, Weijun Pan, Ziming Xu, Jinyan Cai
Aircraft play an important role in transportation. Thus, improving the efficiency of take off and landing at airports under safe conditions has become a key issue in civil aviation. What influences the airport efficiency most is the wake flow generated by aircraft wings. There are many factors that affect wake vortex decay mechanisms, such as atmospheric turbulence, the airport ground, crosswinds, and the mutual induction of vortex systems. A following aircraft may suffer from tilt, roll, stall, sharp pitch, and other dangerous situations that affect flight safety under the influence of downwash when entering the wake region of a leading aircraft. Although the current take off and approaching interval standard (ICAO, 2016) avoids wake vortex hazards, the airport capacity under certain circumstances is severely limited.