Development of a next generation airplane, which cruises near sonic speed, received considerable attention in 2002. To investigate aerodynamic characteristics and validity of CFD codes as a design tool in this new cruise condition, detailed wind tunnel test and CFD validation study was conducted in near sonic regime about the NEXST-1, unpowered supersonic experimental vehicle as a cooperative r...

This paper presents a comprehensive conversion loss analysis of the Power Conditioning System (PCS) for a grid connected Permanent Magnet Generator (PMG) and a Wound Rotor Induction Generator (WRIG) based small wind turbine system. The main focus of the loss analysis is the conduction and switching losses in the semiconductor devices and PCS. The analysis reveals that the WRIG based system with...

Magnetohydrodynamic (MHD) turbulence in the solar wind is observed to show the spectral behavior of classical Kolmogorov fluid turbulence over an inertial subrange and departures from this at short wavelengths, where energy should be dissipated. Here we present the first measurements of the electric field fluctuation spectrum over the inertial and dissipative wavenumber ranges in a β & 1 plasma...

The intense Compton cooling of ultra-relativistic electrons in the Klein-Nishina regime in radiation dominated environments, such as that found in the Galactic Centre, may result in radically different electron spectra than those produced by Synchrotron cooling. We explore these effects and their impact on the X-ray and γ-ray spectra produced in electron accelerators in this region in compariso...

Close to the onset of Aeolian particle transport through saltation we find in wind tunnel experiments a regime of discontinuous flux characterized by bursts of activity. Scaling laws are observed in the time delay between each burst and in the measurements of the wind fluctuations at the fluid threshold Shields number θc. The time delay between each burst decreases on average with the increase ...

Magnetohydrodynamic (MHD) turbulence in the solar wind is observed to show the spectral behavior of classical Kolmogorov fluid turbulence over an inertial subrange and departures from this at short wavelengths, where energy should be dissipated. Here we present the first measurements of the electric field fluctuation spectrum over the inertial and dissipative wave number ranges in a Beta > or a...

The Genesis Discovery mission returned solar matter in the form of the solar wind with the goal of obtaining precise solar isotopic abundances (for the first time) and greatly improved elemental abundances. Measurements of the light noble gases in regime samples demonstrate that isotopes are fractionated in the solar wind relative to the solar photosphere. Theory is required for correction. Mea...

The signal processing aspect of a 2-μm wavelength coherent Doppler lidar system under development at NASA Langley Research Center in Virginia is investigated in this paper. The lidar system is named VALIDAR (validation lidar) and its signal processing program estimates and displays various wind parameters in real-time as data acquisition occurs. The goal is to improve the quality of the current...