DARK MATTER DENSITY AS A FUNCTION OF THE TIME OF YEAR

Until recently I had been assuming from the data taken that the dark matter wave velocity on earth is close to 25 m/s. The density of dark matter is apparently proportional to the reciprocal of the wave velocity squared. I found velocities for 2011 using my interchange method described in my 2010 Physics Essays' article. The data therein was taken near the first of May 2009. Beginning in September 2011, the large amplitude wave velocity was found near 1000 m/s, and increased to more than 20,000 m/s in October in the Northern hemisphere. Apparently one has to take into account the location and tilt of the earth in the dark matter standing wave pattern produced by the sun. I assume that the earth lies at least partially on an antinode for part of the year rather than on a node compared to most of the other planets. The antinode location and dark matter density varies on the earth's surface because the earth's orbit location and tilt varies as a function of the time of year with the tilt determining spring, summer, and winter in the Southern and Northern hemispheres.

Scaling Interface Length Increase Rates in Richtmyer–Meshkov Instabilities

The interface area increase produced by large-amplitude wave refraction through an interface that separates fluids with different densities can have important physiochemical consequences, such as a fuel consumption rate increase in the case of a shock–flame interaction. Using the results of numerical simulations along with a scaling analysis, a unified scaling law of the interface length increase was developed applicable to shock and expansion wave refractions and both types of interface orientation with the respect to the incoming wave. To avoid a common difficulty in interface length quantification in the numerical tests, a sinusoidally perturbed interface was generated using gases with different temperatures. It was found that the rate of interface increase correlates almost linearly with the circulation deposited at the interface. When combined with earlier developed models of circulation deposition in Richtmyer–Meshkov instability, the obtained scaling law predicts dependence of interface dynamics on the basic problem parameters.

Flow and Hydraulics near the Sill of Hood Canal, a Strongly Sheared, Continuously Stratified Fjord

Hood Canal, a long fjord in Washington State, has strong tides but limited deep-water renewal landward of a complex constriction. Tide-resolving hydrographic and velocity observations at the constriction, with a depth-cycling towed body, varied markedly during three consecutive years, partly because of stratification variations. To determine whether hydraulic control is generally important and to interpret observations of lee waves, blocking, and other features, hydraulic criticality is estimated over full tidal cycles for channel wide internal wave modes 1, 2, and 3, at five cross-channel sections, using mode speeds from the extended Taylor–Goldstein equation. These modes were strongly supercritical during most of ebb and flood on the gentle seaward sill face and for part of flood at the base of the steep landward side. Examining local criticality along the thalweg found repeated changes between mode 1 being critical and supercritical approaching the sill crest during flood, unsurprising given local minima and maxima in the cross-sectional area, with the sill crest near a maximum. Density crossing the sill sometimes resembled an overflow with an internal hydraulic control at the sill, followed by a hydraulic jump or lee wave. Long-wave speeds, however, suggest cross waves, particularly along the shallower gentler side, where flow downstream of a large-amplitude wave was uniformly supercritical. Supercritical approaching the sill, peak ebb was critical to mode 1 and supercritical to modes 2 and 3 at the base while forming a sluggish dome of dense water over the sill. Full interpretation exceeds observations and existing theory.