scispace - formally typeset
Search or ask a question
Topic

Oblique shock

About: Oblique shock is a research topic. Over the lifetime, 6551 publications have been published within this topic receiving 119823 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, the authors combined UV and white light (WL) coronagraphic data to derive the full set of plasma physical parameters along the front of a shock driven by a Coronal Mass Ejection.
Abstract: In this work UV and white light (WL) coronagraphic data are combined to derive the full set of plasma physical parameters along the front of a shock driven by a Coronal Mass Ejection. Pre-shock plasma density, shock compression ratio, speed and inclination angle are estimated from WL data, while pre-shock plasma temperature and outflow velocity are derived from UV data. The Rankine-Hugoniot (RH) equations for the general case of an oblique shock are then applied at three points along the front located between $2.2-2.6$ R$_\odot$ at the shock nose and at the two flanks. Stronger field deflection (by $\sim 46^\circ$), plasma compression (factor $\sim 2.7$) and heating (factor $\sim 12$) occur at the nose, while heating at the flanks is more moderate (factor $1.5-3.0$). Starting from a pre-shock corona where protons and electrons have about the same temperature ($T_p \sim T_e \sim 1.5 \cdot 10^6$ K), temperature increases derived with RH equations could better represent the protons heating (by dissipation across the shock), while the temperature increase implied by adiabatic compression (factor $\sim 2$ at the nose, $\sim 1.2-1.5$ at the flanks) could be more representative of electrons heating: the transit of the shock causes a decoupling between electron and proton temperatures. Derived magnetic field vector rotations imply a draping of field lines around the expanding flux rope. The shock turns out to be super-critical (sub-critical) at the nose (at the flanks), where derived post-shock plasma parameters can be very well approximated with those derived by assuming a parallel (perpendicular) shock.

34 citations

Journal ArticleDOI
TL;DR: In this paper, experimental studies using shock tubes are presented of the mixed Type flow around a circular cylinder placed normal to the general flow of Mach number 1.35, 1.8, 2.7, 3.5, 4.0, and 6.0.
Abstract: Experimental studies using shock tubes are presented of the mixed Type flow around a circular cylinder placed normal to the general flow of Mach number 1.35, 1.8, 2.7, 3.5, 4.0, and 6.0. With the Mach-Zehnder interferometer and schlieren method the followings were measured: a) shape of detached shock wave, b) distance d of shock wave from the cylinder nose, c) pressure coefficient C p on the surface of the cylinder, d) density distribution behind the detached shock, e) streamlines in subsonic region.

34 citations

Journal ArticleDOI
TL;DR: In this article, a simple dynamic system analysis is used to give examples of strong, weak overdriven, and weak underdriven oblique detonations for a fluid that is taken to be an inviscid, calorically perfect ideal gas undergoing a two-step irreversible reaction with the first step exothermic and the second step endothermic.
Abstract: A simple dynamic systems analysis is used to give examples of strong, weak overdriven, and weak underdriven oblique detonations. Steady oblique detonations consisting of a straight lead shock attached to a solid wedge followed by a resolved reaction zone structure are admitted as solutions to the reactive Euler equations. This is demonstrated for a fluid that is taken to be an inviscid, calorically perfect ideal gas that undergoes a two‐step irreversible reaction with the first step exothermic and the second step endothermic. This model admits solutions for a continuum of shock wave angles for two classes of solutions identified by a Rankine–Hugoniot analysis: strong and weak overdriven waves. The other class, weak underdriven, is admitted for eigenvalue shock‐wave angles. Chapman–Jouguet waves, however, are not admitted. These results contrast those for a corresponding one‐step model that, for detonations with a straight lead shock, only admits strong, weak overdriven, and Chapman–Jouguet solutions.

34 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe an incident shock wave in a self-similar Mach number static pressure reflection point; point where RR = wave angle X,x' = first and second triple-point trajectory angles.
Abstract: incident shock wave in shock tube kink in CMR reflected wave R first and second Mach stems in DMR self-similar Mach number (M) , = (u + v)/a Mach reflection (SMR, CMR, DMR, TDMR) incident shock wave (/) Mach number static pressure reflection point; point where RR =wave angle X,x' = first and second triple-point trajectory angles

34 citations

Journal ArticleDOI
TL;DR: In this paper, an aspheric lens-shaped transparent test section made of acrylic PMMA (polymethyl methacrylate) with an inner spherical cavity was designed and constructed.
Abstract: The paper describes results of experiments of a converging spherical shock wave reflected from a spherical wall. In order to visualize the motion and the flow field behind the shock waves, an aspheric lens-shaped transparent test section made of acrylic PMMA (polymethyl methacrylate) with an inner spherical cavity was designed and constructed. This test section made optical flow visualization with collimated object beams possible. Spherical shock waves were produced at the centre of the spherical cavity by explosion of silver azide pellets ranging from 1.0 to 10.0 mg with corresponding energies of 1.9 to 19 J. The charges were ignited by irradiation of a pulsed Nd:YAG laser beam. Pressures were also measured at two points with pressure transducers mounted flush at the inner wall of the test section. The pellet was simultaneously ignited on two sides or was shaped to produce a uniform diverging spherical shock wave. This spherically diverging shock wave was reflected from the spherical inner wall of the test section to form a converging spherical shock wave. We visualized the shock-wave motion by using double exposure holographic interferometry and time-resolved high-speed video recording. The sequence of diverging and converging spherical shock-wave propagations and their interaction with gaseous explosion products were observed. The convergence, acceleration and stability of the imploding shock wave in the test section were studied.

34 citations


Network Information
Related Topics (5)
Boundary layer
64.9K papers, 1.4M citations
87% related
Turbulence
112.1K papers, 2.7M citations
86% related
Reynolds number
68.4K papers, 1.6M citations
86% related
Laminar flow
56K papers, 1.2M citations
83% related
Vortex
72.3K papers, 1.3M citations
80% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202369
2022142
2021106
202090
201992
2018102