Wind tunnel studies of circulation control elliptical airfoils

Effects of blown jets on the lift and drag of cambered elliptical airfoils are described. Performance changes due to a splitter plate attached to the lower surface of an elliptical airfoil near the trailing edge with and without blowing are indicated. Lift and drag characteristics of airfoils with two blown jets are compared with airfoils with single blowing jets. Airfoil designs that vary the location of a second jet relative to a fixed jet are described

Gauge Invariant Regularization of Quantum Field Theory on the Light-Front

Gauge invariant regularization of quantum field theory in the framework of Light-Front (LF) Hamiltonian formalism via introducing a lattice in transverse coordinates and imposing boundary conditions in LF coordinate $x^-$ for gauge fields on the interval $|x^-|\le L$ is considered. The remaining ultraviolet divergences in the longitudinal momentum $p_-$ are removed by gauge invariant finite mode regularization. We find that LF canonical formalism for the introduced regularization does not contain usual most complicated second class constraints connecting zero and nonzero modes of gauge fields. The described scheme can be used either for the regularization of conventional gauge theory or for gauge invariant formulation of effective low-energy models on the LF. The lack of explicit Lorentz invariance in our approach leads to difficulty with defining the vacuum state. We discuss this difficulty, particulary, in the connection with the problem of taking the limit of continuous space.Comment: LaTeX 2.09, 15 pages, Proceedings of "12th V.Fock School of Physics", St-Petersburg 200

Zero-mode contribution to the light-front Hamiltonian of Yukawa type models

Light-front Hamiltonian for Yukawa type models is determined without the framework of canonical light-front formalism. Special attention is given to the contribution of zero modes.Comment: 14 pages, Latex, revised version with minor changes, Submitted to J.Phys.

Impact of forced and internal climate variability on changes in convective environments over the eastern United States

2022 Summer.Includes bibliographical references.Hazards from convective weather and severe storms pose a serious threat to the continental United States (CONUS). Previous studies have examined how future projected changes in climate might impact the frequency and intensity of severe weather using simulations with both convection permitting regional models and coarser-grid Earth system models. However, most of these studies have been limited to single representations of the future climate state with little insight into the uncertainty of how the population of convective storms may change. To more thoroughly explore this aspect, we utilize a large-ensemble of climate model simulations to investigate the forced response and how it may be modulated by internal variability. Specifically, we use daily data from an ensemble of 50 climate simulations with the most recent version of the Community Earth System Model (CESM) to examine changes in the severe weather environment over the eastern CONUS during boreal spring from 1870-2100. Our results indicate that the large-scale convective environment changed little between 1870 and 1990, but from then throughout the 21st century, convective available potential energy increases while 0-6 km vertical wind shear and convective inhibition decreases (increased stability). While the forced changes in these variables are robust both in space and time, we show that they are likely to be modified significantly by internal climate variability. This effect can either act to significantly enhance the forced response or conversely, suppress it in such a way that produces changes in the convective environment that are opposite to the forced response. The time evolution of bivariate distributions of convective indices illustrates that future springtime convective environments over the eastern CONUS will be characterized by relatively less frequent, but deeper and more intense convection. Future convective environments will also be less supportive of the most severe convective modes and their associated hazards