1,740 research outputs found
Turbofan noise generation. Volume 1: Analysis
Computer programs were developed which calculate the in-duct acoustic modes excited by a fan/stator stae operating at subsonic tip speed. Three noise source mechanisms are included: (1) sound generated by the rotor blades interacting with turbulence ingested into, or generated within, the inlet duct; (2) sound generated by the stator vanes interacting with the turbulent wakes of the rotors blades; and (3) sound generated by the stator vanes interacting with the mean velocity deficit wakes of the rotor blades. The fan/stator stage is modeled as an ensemble of blades and vanes of zero camber and thickness enclosed within an infinite hard-walled annular duct. Turbulence drawn into or generated within the inlet duct is modeled as nonhomogeneous and anisotropic random fluid motion, superimposed upon a uniform axial mean flow, and convected with that flow. Equations for the duct mode amplitudes, or expected values of the amplitudes, are derived
Turbofan noise generation. Volume 2: Computer programs
The use of a package of computer programs developed to calculate the in duct acoustic mods excited by a fan/stator stage operating at subsonic tip speed is described. The following three noise source mechanisms are included: (1) sound generated by the rotor blades interacting with turbulence ingested into, or generated within, the inlet duct; (2) sound generated by the stator vanes interacting with the turbulent wakes of the rotor blades; and (3) sound generated by the stator vanes interacting with the velocity deficits in the mean wakes of the rotor blades. The computations for three different noise mechanisms are coded as three separate computer program packages. The computer codes are described by means of block diagrams, tables of data and variables, and example program executions; FORTRAN listings are included
Annual Survey of Virginia Law: Property Law
Numerous court decisions affecting property law in Virginia have been announced since the last edition of this portion of the annual survey. Significant decisions of the Supreme Court of Virginia, Virginia Court of Appeals and the Court of Appeals for the Fourth Circuit are discussed in Section I of this article. Furthermore, a prolific General Assembly has passed various legislation affecting property law ranging from condominiums to zoning. Significant legislation is discussed in Section II
The Nonlinear Debye-Onsager Relaxation Effect in Weakly Ionized Plasmas
A weakly ionized plasma under the influence of a strong electric field is
considered. Supposing a local Maxwellian distribution for the electron momenta
the plasma is described by hydrodynamic equations for the pair distribution
functions. These equations are solved and the relaxation field is calculated
for an arbitrary field strength. It is found that the relaxation effect becomes
lower with increasing strength of the electrical field.Comment: 4 pages, 1 figur
Lower tick sizes and futures pricing efficiency: evidence from the emerging Malaysian market
We provide robust evidence of the impact on spot market liquidity and the pricing efficiency of FBM-FKLI index futures following the introduction of lower tick sizes for the stocks listed in the Bursa Malaysia. Our findings show a significant increase in unexpected trading volume and the speed of mean reversion of the futures mispricing. We find that the increase in the unexpected trading volume of the underlying stocks helps in reducing inter-market price discrepancies. The findings offer new evidence that lowering of tick sizes improves pricing efficiency in the Malaysian futures market
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