Capillary waves at the liquid-vapor interface and the surface tension of water models

Capillary waves occurring at the liquid-vapor interface of water are studied using molecular dynamics simulations. In addition, the surface tension, determined thermodynamically from the difference in the normal and tangential pressure at the liquid-vapor interface, is compared for a number of standard three- and four-point water models. We study four three-point models (SPC/E, TIP3P, TIP3P-CHARMM, and TIP3P-Ew) and two four-point models (TIP4P and TIP4P-Ew). All of the models examined underestimate the surface tension; the TIP4P-Ew model comes closest to reproducing the experimental data. The surface tension can also be determined from the amplitude of capillary waves at the liquid-vapor interface by varying the surface area of the interface. The surface tensions determined from the amplitude of the logarithmic divergence of the capillary interfacial width and from the traditional thermodynamic method agree only if the density profile is fitted to an error function instead of a hyperbolic tangent function.Comment: 11 pages, 8 figures, 7 tables. Accepted for publication in J. Chem. Phys. [v2: Added references, corrected minor errors

F-15 inlet/engine test techniques and distortion methodologies studies. Volume 7: Cross correlation functions.

Cross correlation function plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle

F-15 inlet/engine test techniques and distortion methodologies studies. Volume 3: Power spectral density plots

Power spectral density plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle

F-15 inlet engine test techniques and distortion methodologies studies. Volume 9: Stability audits

Stability audit plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle

F-15 inlet/engine test techniques and distortion methodologies studies. Volume 2: Time variant data quality analysis plots

Time variant data quality analysis plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle

Accretion Disk Temperatures of QSOs: Constraints from the Emission Lines

QSO emission-line spectra are compared to predictions based on theoretical ionizing continua of accretion disks. Observed line intensities do not show the expected trend of higher ionization with higher accretion disk temperature as derived from the black hole mass and accretion rate. This suggests that, at least for accretion rates close to the Eddington limit, the inner disk does not reach temperatures as high as expected from standard disk theory. Modified radial temperature profiles, taking account of winds or advection in the inner disk, achieve better agreement with observation. This conclusion agrees with an earlier study of QSO continuum colors as a function of disk temperature. The emission lines of radio-detected and radio-undetected sources show different trends as a function of disk temperature.Comment: 9 pages, 8 figures, submitted to Ap

F-15 inlet/engine test techniques and distortion methodologies studies. Volume 8: Cross spectral density plots

Cross spectral density plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle

F-15 inlet/engine test techniques and distortion methodologies studies. Volume 4: Autocorrelation functions

Autocorrelation function plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle

A theoretical study of the aerodynamic characteristics of lifting-body entry vehicles Summary report, Mar. 1965 - Mar. 1966

Aerodynamic characteristics of lifting-body entry vehicle

F-15 inlet/engine test techniques and distortion methodologies studies. Volume 5: Effect of filter cutoff frequency on turbulence plots

The effect of filter cutoff frequency on turbulence plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle