# Shock wave through a liquid metal filled steel tube

• BrandonBerchtold
In summary, it is possible for a shock wave to transmit a pressure pulse through a liquid-filled steel tube, but the pressure pulse must be short enough and the tube wall must be able to withstand the peak pressure without yielding. The speed of sound in the liquid and the tube material can also affect the transmission of the pressure pulse. Additionally, the presence of a shock wave can cause different types of stresses in the tube compared to other types of pressure pulses.
BrandonBerchtold
TL;DR Summary
Would an A36 steel tube be able to axially transmit a shock wave with a peak pressure higher than the yield strength of the steel tube?
Would an A36 steel tube filled with liquid mercury be able to transmit a shock wave longitudinally through the liquid mercury with a peak pressure higher than the yield strength of the steel tube? My thinking is that since the shock wave is traveling normal to the tube wall, it should not be interacting with the tube wall. However, if the shock wave is pictured to be a disk of high pressure mercury, this disk should be exerting a force, equal to the peak shock pressure, outwards into the tube wall (granted this disk would be traveling at the speed of sound in mercury and not have long to exert said force on the walls).

If we assume a short duration pressure pulse normal to the tube wall, then the sequence of events is as follows:
1) The pressure pulse applies force to the tube wall. The force is large enough to yield the wall.
2) The tube wall has elasticity and inertial mass, so it starts to accelerate outward.
3) As the tube wall moves outward, the material stress increases.
4) If the pressure pulse ends before the tube wall yields, then the tube wall does not yield. This ignores tube wall inertia, but that effect should be small.
5) I am assuming that the shock wave exerts pressure equally in all directions.

So, yes it is possible for the pressure to be large enough to yield the tube wall, without yielding the tube wall. But it may or may not be possible to create a pressure pulse short enough for that to happen.

Last edited:
ChemAir, berkeman and BrandonBerchtold
Will there actually be a “shock wave” ?

The speed of sound is 5,130 m/s in iron, but only 1,450 m/s in mercury. The pressure step that starts in the mercury will gradually enter the iron and race ahead of the pulse that remains in the mercury. Some of that energy will reenter the mercury well ahead of the pulse and so rapidly reduce the slope of the pressure step in the mercury.

The pulse in the mercury will be traveling along the steel wall, so some energy will couple across the impedance mismatch into the steel. I expect the low speed in mercury will form a greater amplitude step than it will in the iron. That may attenuate the stress that appears in the iron.

Pressure in a cylindrical tube causes a hoop stress that is twice the longitudinal stress, which explains why pipes split longitudinally. Will the same be true for a slow pressure step inside the tube?

BrandonBerchtold
How about something like water hammer?

BrandonBerchtold
Water hammer is a transmission line effect. The liquid is not compressible.

A shock wave pressure step compresses and heats a gas, which increases the speed of sound behind the step, so it accelerates the velocity of the shock front and keeps the step sharp.

## 1. What is a shock wave through a liquid metal filled steel tube?

A shock wave through a liquid metal filled steel tube is a high-pressure wave that travels through a tube filled with liquid metal, causing a sudden increase in pressure and temperature.

## 2. How is a shock wave through a liquid metal filled steel tube created?

A shock wave through a liquid metal filled steel tube is created when a high-energy source, such as an explosion or a high-velocity projectile, impacts the tube, causing a rapid compression and expansion of the liquid metal inside.

## 3. What are the potential applications of studying shock waves through liquid metal filled steel tubes?

Studying shock waves through liquid metal filled steel tubes can have various applications, including in the fields of materials science, engineering, and defense. It can help understand the behavior of materials under extreme conditions and improve the design of structures to withstand high-pressure events.

## 4. What factors can affect the propagation of a shock wave through a liquid metal filled steel tube?

The propagation of a shock wave through a liquid metal filled steel tube can be affected by various factors, including the type and properties of the liquid metal, the geometry and material of the tube, and the energy and velocity of the impact source.

## 5. What techniques are used to study shock waves through liquid metal filled steel tubes?

To study shock waves through liquid metal filled steel tubes, scientists use techniques such as high-speed photography, pressure and temperature sensors, and computer simulations. These methods allow for the visualization and measurement of the shock wave's behavior and its effects on the tube and liquid metal.

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