We present a re-analysis of the optical spectroscopic data on SS 433 from the last quarter-century and demonstrate that these data alone contain systematic and identifiable deviations from the traditional kinematical model for the jets: variations in jet speed which agree with our analysis of recent radio data, in precession cone angle and in phase. We present a simple technique for separating ...

We consider the polarization properties of optically thin synchrotron radiation emitted by relativistically moving electron–positron jets carrying large-scale helical magnetic fields. In our model, the jet is cylindrical, and the emitting plasma moves parallel to the jet axis with a characteristic Lorentz factor Γ. We draw attention to the strong influence that the bulk relativistic motion of t...

We consider the time-dependent evolution of a relativistic jet following its breakout through the surface of a massive compact star, as envisaged in the collapsar model of gamma-ray bursts. At breakout, the jet is tightly collimated by the pressure of its hot cocoon, which is created as the jet traverses the star. After breakout, the cocoon pressure drops and the jet expands toward its natural ...

We study the production of direct photons in e+eannihilation +ee -+ y + hadrons where the high energy photon is emitted at a large angle to a hadron jet or is a fragment of the jet itself. We give the angle and energy dependence of the cross section for photons radiated from the final state quarks, the initial state leptons, and also the interference term. Large angle radiation by the quarks is...

Multi-injector system is potential to improve thermal efficiency and NOx emission of diesel engine at the same time. In order optimize combustion Marine medium speed engine, with a multi-injector simulated analyzed by CFD software Converge. this research, two injectors are installed side cylinder head while central injector maintained. Various injection directions strategies fuel spray combusti...

Numerical modeling of direct hydrogen injection and in-cylinder mixture formation is performed in this paper. Numerical studies on direct-injection hydrogen engines are very limited due mainly to the complexity in modeling the physical phenomena associated with the high-velocity gas jet. The high injection pressure will result in a choked flow and develop an underexpanded jet at the nozzle exit...

We consider the polarization properties of optically thin synchrotron radiation emitted by relativistically moving electron–positron jets carrying large-scale helical magnetic fields. In our model, the jet is cylindrical, and the emitting plasma moves parallel to the jet axis with a characteristic Lorentz factor Γ. We draw attention to the strong influence that the bulk relativistic motion of t...

The jet structure in gamma-ray burst (GRB) sources is still largely an open question. The leading models invoke either (i) a roughly uniform jet with sharp edges, or (ii) a jet with a narrow core and wide wings where the energy per solid angle drops as a power law with the angle θ from the jet symmetry axis. Recently, a two component jet model has also been considered, with a narrow uniform jet...

Downfall flows from different outlet hydraulic structures such as culverts and jetsthrowingtothe erodible downstream bed cause scour hole and changes in the downstream bed topography. Therefore,by performing some physical modeling tests on culvert jet flow under different angles, changes in the downstream bed topography under the effect of different parameters such as flow rate, depth of the ta...

This study concerns numerical simulation, modeling and optimization of aerodynamic stall control using a synthetic jet actuator. Thenumerical simulation was carried out by a large-eddy simulation that employs a RNG-based model as the subgrid-scale model. The flow around a NACA0015 airfoil, including a synthetic jet located at 10 % of the chord, is studied under Reynolds number Re = 12.7 × 106 a...