Search results for " turbolence"
showing 3 items of 3 documents
A NON CONVENTIONAL UAV IN GROUND EFFECT: ESTIMATION OF STATE AND TURBULENCE VIA EXTENDED KALMAN FILTER
2009
ABSTRACT This paper discusses the synthesis of an Extended Kalman Filter (EKF) to perform both wind velocities and state estimation for a non conventional UAV flying in ground effect. Since, in IGE flight, motions into the symmetry plane are of primary concern, the study focuses on the longitudinal aircraft dynamics. The proposed estimator requires measurement of few flight variables, easily obtainable by means of conventional sensors; besides, it does not use Inertial Measurement Unit (IMU). To simulate a low cost sensing equipment, the model outputs are corrupted by white noise of relatively high standard deviation. Furthermore, to cope with the low rate of the GPS with respect to the oth…
Extended Thermodynamics of Turbolent Superfluids:Nonlinear Costitutive Theory
2008
In this paper we extend to nonlinear regimes a thermodynamical model of inhomogeneous superfluid turbulence previously formulated. The theory chooses as fundamental fields the density, the velocity, the energy density, the heat flux and the averaged vortex line length per unit volume. The relations which constrain the constitutive quantities are deduced from the entropy principle, using the Liu method of Lagrange multipliers. Using a Legendre transformation, in the paper it is shown that the constitutive theory is determined by the choice of only two scalar functions of the intrinsic Lagrange multipliers.
Speeds of discontinuity waves in turbulent superfluids
2012
In this work, using a hydrodynamical model previously formulated, the possible modes of propagation of discontinuity waves in turbulent superfluids are studied in the nonlinear regimes. The field equations are written down, then the wave speeds are determined in a constant state.