Questions tagged [shock-waves]

A shock wave is the final stage of a nonlinearly steepening wave that has reached a balance between steepening and energy dissipation resulting in a discontinuity.

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Can the dynamic between high speed sound media and slow one preduce shock wave?

Suppose there is two long media that in one of them the speed of sound is high and in one of them is slow. Would the vibration in the one with the higher speed of sound would cause shock wave in the ...
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Clapping-like sound from large planar object hitting a surface

I am trying to understand the behavior of air when a large, planar object hits a parallel surface at a high velocity, thus forcing the initially static air outwards, and creating a sound wave. This is ...
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Utility of Burger's equation in the study of shock waves

Consider the viscous Burger's equation, $$ \frac{\partial u}{\partial t}+u \frac{\partial u}{\partial x}-\nu \frac{\partial^{2} u}{\partial x^{2}}=0, \tag{1} $$ with $\nu>0$ the kinematic viscosity....
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Are seismic waves and shock waves same?

Are shock waves (those produced by high speed jets) and seismic waves (produced during earthquake) the same? In many places I have seen seismic waves referred to as shock waves. So are these two same?
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How would high-explosives interact with the shockwaves around a hypersonic weapon?

This is a proxy for a question from a friend. I'm an aerospace engineer so I have some domain-knowledge on compressible flow but less about missile design and even less about explosives. I also ...
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Gravitational waves manifestation of 'physical' spacetime?

When a stone is thrown in water, water waves are created. The stone imparts its kinetic energy to water. Likewise a sound speaker imparts its kinetic energy to air molecules. When an electron falls ...
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Shockwaves in a colllision of two cylinders

On Motion Mountain's first volume (fall, flow and heat) by Christoph Schiller, page 128, the author asks the following puzzle: A surprising effect is used in home tools such as hammer drills. We ...
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Is submersion in a canal a good way to shelter from a nuclear strike?

I live 1.5 miles from the center of a city in a nuclear-armed country, and an adversarial country has just put its nuclear forces on high alert during a time of extraordinary geopolitical tension. I ...
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Theoretical rocket engine based on plasma shock waves particle acceleration

Credits for the article - https://www.quantamagazine.org/cosmic-map-of-ultrahigh-energy-particles-points-to-long-hidden-treasures-20210427 Can this mechanism be used to speed up gas particles to ...
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Sound wave travelling from high impedance to low impedance medium, what will be the reflection & transmission coeffiecient?

Let us assume that a wave propagates in the direction perpendicular to the flat surface of discontinuity. When the characteristic impedance of the medium of medium 0 (where the incident and reflected ...
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Curved shocks and vorticity generation

In fluid dynamics, it is known that curved shocks (which are common, e.g., in bowshocks) generate vorticity. I am looking for a quantitative derivation.
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Can a microphone on a supersonic aircraft hear noises coming from outside?

This webpage includes the following question/answer that includes the italicized text saying that pilots of a supersonic jet cannot hear sounds from outside the aircraft. Do pilots of a supersonic ...
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Normal Shockwaves and its Thermodynamics

Please read this page before going to my question. When we derive the relation between Mach no. to the left side of the shock wave (M1) and that to the right side of the shock wave (M2),we do that ...
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Can you break the sound barrier without creating a loud bang? [duplicate]

The loud bang of the breaking of the sound barrier is known. But it sureley has to do with acceleration. High speed jets accelerate with $11.1 m/s^2$ the air gets compressed and has barely time to ...
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Conceptual explanation for subsonic nozzle VS supersonic nozzle

A nozzle is a device that increases the velocity of a fluid in the expanse of pressure energy drop of the fluid (The Bernoulli principle). Now how can we explain (conceptually, no math) why a subsonic ...
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Plage regions data

Plages are phenomena of stellar activity. Where can I find openly-accessible data of plage regions of the Sun with other parameters such as faculae region, magnetic field, etc?
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Cherenkov Radiation: Does it need to be faster than light in the certain medium?

I understand that when a charged particle moves through a medium and excites the atoms nearby, it produces a blue light when the atoms 'de-excite" However, I don't understand why it has to be ...
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How are shockwaves created if no particle goes around the wings at supersonic speed?

so,the title could be a bit misleading, let me elaborate: whenever studying aerodynamics, the explanation starts with considering the wing of a plane still, and the flow of air arriving from either ...
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Direction of supersonic shockwave on a bullet with lateral velocity

When a bullet travels at supersonic speeds, it generates a shock-wave. For a bullet traveling in a straight path, the shock-wave is oriented in the same direction as the bullet. But if a bullet is ...
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Is the internal energy of a supernova blast wave always 72% of the initial energy released?

In Astrophysics, an A-Z Introduction, Page 67, Patrick Betts states that in the Sedov-Taylor solution for a blast wave, the temperature of a supernova shell decreases over time, but the internal ...
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How to determine stability of shocks in hydrodynamics?

Shock waves are very common in relativistic as well as non-relativistic hydrodynamics. The stability of the shocks are usually studies using numerical simulations. However, I am interested to know ...
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What is the nature behind the periodicity of the Mach diamonds?

I've heard very interesting and sometimes contradictory hypothesis about why the Mach Diamonds have well defined spatial periodicities. I am not sure I understand most of them, and I cannot exclude ...
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Physical interpretation of eyewitness reports - Tunguska Event

From this site, I found some eyewitness reports about the Tunguska Event (30th June 1908). One of them goes like this: "I was sitting on the porch of the house at the trading station, looking ...
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Can a ground shockwave affect something mid-air? [closed]

Let's say if something were to hit the ground very fast and hard with no explosion just force, would it affect something mid-air like a bird that is not touching the ground?
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What is the expected effect of a Tsar-scale bomb at the antipodal point of the detonation site?

Background Obviously, being next to explosions is bad. The farther away one is from the explosion, the larger the hemisphere of he shock wave is, and so the more the energy from the explosion is ...
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Why the total temperature remains constant through shock wave? [closed]

We know that total temperature is sum of static and dynamic temperature. If static temperature increases through the shock wave, then how total temperature remains constant? It must increase and not ...
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What caused the 3rd shock wave in this nuclear explosion?

In 1958, the United States conducted a series of nuclear tests at the Pacific Proving Grounds in the Marshall Islands as part of Operation Hardtrack. In some recently remastered footage of the Wahoo ...
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How are shocks generated in a linear one-dimensional lattice?

I am struggling to understand shocks in a one-dimensional lattice. Say I have a one dimensional lattice with a linear spring constant $k$ and lattice spacing $a$. If the particles in the lattice has ...
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Why does the transverse Alfven mode not undergo wave steepening and hence resulting in shock waves?

Initial Question: I am currently working through the second edition of Introduction to Plasma Physics by Donald A. Gurnett & A. Bhattacharjee In section 8.3.8 on page 304, they state that: .. on ...
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Wave drag at high altitudes is high or low?

Density decreases with increasing altitude. Consequently, Reynolds number decreases and boundary layer thickness increases, so friction drag and pressure drag increase. What about wave drag? Does wave ...
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The relation between shockwave thickness and shockwave strength

What is the relation between shockwave thickness and shockwave strength? I mean with increasing altitude and increase shockwave thickness, shock become stronger or weaker? Defining strength of a ...
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How can supersonic accretion flows exist in astrophysical scenarios?

I often hear about supersonic accretion flows in astrophysical scenarios: for example, the inner parts of the accretion disk around a supermassive black hole or cold filaments accreting into galaxies ...
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Can a sonic boom be a standing wave?

If I understand the sonic boom of a supersonic aircraft correctly, it can be abstracted as an (ideally) conical wavefront dragging behind the vehicle, with the “boom” being the perception of the edge ...
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How would a warp bubble interact with an atmosphere? [closed]

What would happen if a warp drive entered the Earth atmosphere? IIRC some scientists have created mathematical models that have shown that warp bubbles that don't exceed the speed of light may be ...
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Interaction of supersonic wind with static Inter-Stellar Medium (ISM)

Recently I was studying about the interaction of supersonic flow (wind) with a slowly flowing medium. In a paper by Dyson, Falle, and Perry 1980 MNRAS stated that when a supersonic wind impinged upon ...
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The physics of flow choking

Can someone explain what happens in a fluid flow at a molecular level during flow choking. Take for example a Rayleigh flow (flow with heat addition) what happens at a micro level which prevents a ...
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9 votes
5 answers
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Why does a blast wave travel faster than sound?

https://en.wikipedia.org/wiki/Blast_wave#Characteristics_and_properties says: "A blast wave travels faster than the speed of sound and the passage of the shock wave usually lasts only a few ...
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Why don't CPU fans have the buzzsaw effect (as in planes), even when their blades spin faster than 5k RPM? [closed]

I saw my CPU fan using HWinfo spinning faster than 5k RPM, in which the buzzsaw effect starts in an A3xx plane. Why doesn't my CPU fan do the buzzsaw effect, even though it's spinning faster than 5k ...
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The pressure fluctuations in an incompressible flow

I am reading the article by Zu and He (Phase-field-based lattice Boltzmann model for incompressible binary fluid systems with density and viscosity contrasts, Physical review E, 2013). There the ...
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Location of Compression shock wave in de laval nozzles

Is there a way to compute the location of an compression shock inside de laval nozzles as a function of either the the pressure ratio or the area ratio in the divergent part of the nozzle?
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Wave drag in the interstellar medium

In Earth's atmosphere, an object moving at supersonic or near-supersonic speed experiences wave drag due to the formation of shock waves around the object's leading edge. At high speeds, wave drag is ...
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What is the most efficient particle acceleration mechanism in space and astrophysical plasmas

My question is: What are the most efficient particle acceleration mechanisms in space and astrophysical plasmas: wave-particle interactions, collisionless shocks, or magnetic reconnection? Does it ...
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How acoustic shock waves create and propagate in fluid?

I would like to understand how a shock wave is formed starting from the comservation equations. I know how to obtain a the wave equation with a perturbative approach (i.e assuming very small ...
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Are mach cone and vapor cone the same or not?

I have read numerous articles, claiming that Vapor cone IS NOT the mark that aircraft is passing "sound barrier", or, in other words it is not the visualization of Mach wave But I can't ...
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Falling elevator filled with water

Greetings physics superhumans! If an adult human person is floating in a free-falling elevator, sealed and filled completely with water (no air space), that is damaged on impact in normal elevator ...
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Expansion after a shock wave in a de Laval nozzle

I've performed a CFD of a flow inside a nozzle and I'm evaluating the differences between various settings. I cannot find a reason why after the shock wave formed in the divergence section, the Mach ...
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Why does entropy jump across a shockwave?

Using the Rankine-Hugoniot relations for a shockwave, one can show that entropy jumps across the shock, so that the entropy difference between upstream and downstream conditions is given by $$s_2 - ...
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Can a Mach number be defined for a hot gas fluid element using its own temperature and velocity?

I know that the ratio of an object's speed to the local sound speed is called the Mach number: $$M = \frac{v}{c_s}$$ where $$c_s = \sqrt{\frac{\gamma kT}{\mu m_p}}$$ I have always thought of the Mach ...
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A doubt on Sonic Boom

My textbook says that: Sonic Boom : Sonic boom is an impulsive noise similar to thunder........ From the perspective of the aircraft, the boom appears to be swept backwards as it travels away from ...
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Is it possible to create a shockwave gun (Like in Minority Report) [closed]

I love the gun in Minority Report. It seems to send a shockwave that can throw people and objects back. The gun has a rotating mechanism that triggers the action and loads a charge. Here's it in ...
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