Speed of water jet driven by 300 bar
Clash Royale CLAN TAG#URR8PPP
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In a setting where portals can be opened between one location and another,
Suppose you open a portal of area one square meter, with one end at the surface and the other end at the bottom of an ocean, three kilometers down, where the pressure is three hundred bar. Obviously a jet of water will come through the portal.
What will be the speed of the jet? Equivalently, how many cubic meters per second will come through?
science-based transportation
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up vote
15
down vote
favorite
In a setting where portals can be opened between one location and another,
Suppose you open a portal of area one square meter, with one end at the surface and the other end at the bottom of an ocean, three kilometers down, where the pressure is three hundred bar. Obviously a jet of water will come through the portal.
What will be the speed of the jet? Equivalently, how many cubic meters per second will come through?
science-based transportation
6
Obligatory XKCD
– Cort Ammon
Nov 20 at 7:31
4
Bit of a bigger hole, but obligatory What If XKCD
– CalvT
Nov 20 at 10:10
There would be no high pressure water jet. The portal acts on water particles with force enough to balance the pressure. The second principle of teleportation is that energy required for a body to enter a portal is equal of resulting gain of its potential energy - thus the energy conservation principle is not being violated.
– abukaj
2 days ago
add a comment |
up vote
15
down vote
favorite
up vote
15
down vote
favorite
In a setting where portals can be opened between one location and another,
Suppose you open a portal of area one square meter, with one end at the surface and the other end at the bottom of an ocean, three kilometers down, where the pressure is three hundred bar. Obviously a jet of water will come through the portal.
What will be the speed of the jet? Equivalently, how many cubic meters per second will come through?
science-based transportation
In a setting where portals can be opened between one location and another,
Suppose you open a portal of area one square meter, with one end at the surface and the other end at the bottom of an ocean, three kilometers down, where the pressure is three hundred bar. Obviously a jet of water will come through the portal.
What will be the speed of the jet? Equivalently, how many cubic meters per second will come through?
science-based transportation
science-based transportation
asked Nov 20 at 0:16
rwallace
680414
680414
6
Obligatory XKCD
– Cort Ammon
Nov 20 at 7:31
4
Bit of a bigger hole, but obligatory What If XKCD
– CalvT
Nov 20 at 10:10
There would be no high pressure water jet. The portal acts on water particles with force enough to balance the pressure. The second principle of teleportation is that energy required for a body to enter a portal is equal of resulting gain of its potential energy - thus the energy conservation principle is not being violated.
– abukaj
2 days ago
add a comment |
6
Obligatory XKCD
– Cort Ammon
Nov 20 at 7:31
4
Bit of a bigger hole, but obligatory What If XKCD
– CalvT
Nov 20 at 10:10
There would be no high pressure water jet. The portal acts on water particles with force enough to balance the pressure. The second principle of teleportation is that energy required for a body to enter a portal is equal of resulting gain of its potential energy - thus the energy conservation principle is not being violated.
– abukaj
2 days ago
6
6
Obligatory XKCD
– Cort Ammon
Nov 20 at 7:31
Obligatory XKCD
– Cort Ammon
Nov 20 at 7:31
4
4
Bit of a bigger hole, but obligatory What If XKCD
– CalvT
Nov 20 at 10:10
Bit of a bigger hole, but obligatory What If XKCD
– CalvT
Nov 20 at 10:10
There would be no high pressure water jet. The portal acts on water particles with force enough to balance the pressure. The second principle of teleportation is that energy required for a body to enter a portal is equal of resulting gain of its potential energy - thus the energy conservation principle is not being violated.
– abukaj
2 days ago
There would be no high pressure water jet. The portal acts on water particles with force enough to balance the pressure. The second principle of teleportation is that energy required for a body to enter a portal is equal of resulting gain of its potential energy - thus the energy conservation principle is not being violated.
– abukaj
2 days ago
add a comment |
2 Answers
2
active
oldest
votes
up vote
20
down vote
accepted
Pressure from depth
Hydrostatic pressure is the pressure felt due to the weight of things above it. The pressure at any depth in the ocean can be calculated by the equation for hydrostatic pressure:
$$p - p_0 = rho gh.$$
Here, $p_0$ is atmospheric pressure, and $p$ is pressure at the desired depth. The density of the fluid in the ocean is $rho$, $g$ is the acceleration due to gravity, and $h$ is the height of the column of fluid.
The density of water changes slightly with temperature, and even more slightly with pressure. We will assume a standard value of 1030 kg/m$^3$, which is accurate enough to three significant digits.
$$beginalignp &= 1030text kg/m^3cdot9.81text m/s^2cdot3000text m + 101000text Pa\
&=30.4 text MPaendalign$$
Flow velocity from pressure
Bernoulli's equation governs incompressible flow of fluids at a low Mach number. Since our flow will be well below the speed of sound (as we'll see) and since we've already made an incompressibility assumption by using constant density in the last equation, we can use Bernoulli's equation here. Bernoulli's equation is
$$c = fracv^22 + gz + fracprho$$
where $c$ is a constant, $v$ is the velocity of fluid flow, $z$ is elevation above reference, and $g$, $p$, and $rho$ are as before.
The constant can be factored out of the equation by rewriting the equation in terms of total head, which has units of meters. Before we re-write, we will cancel out $z$ as zero. You are asking for flow through a portal with no depth, there is no net elevation change between the pressure and low pressure zones. The energy head equation is
$$H = fracprho g+fracv^22g.$$
For the zero-velocity situation, i.e. on the ocean side of the portal, we set
$$H = fracp_Orho g.$$
On the atmosphere side of the portal, we set
$$H = fracp_arho g+fracv^22g.$$
Now we can set these two quantities equal to each other to solve for the velocity of the fluid flowing through the portal.
$$beginalignfracp_Orho g &= fracp_arho g + fracv^22g\
frac30400000text Pa1030text kg/m^3cdot9.81text m/s^2 &= frac101000text Pa1030text kg/m^3cdot9.81text m/s^2+fracv^22cdot9.81text m/s^2\
v^2 &= 2cdot9.81cdotleft(frac30400000010100-frac10100010100right)text m^2text/s^2\
v&= 243 text m/s
endalign$$
Volumetric flow from flow velocity
Volumetric flow is expressd as
$$dotV = vA,$$ where $A$ is the area of the portal. Sinc $A = 1text m^2$, we have
$$dotV = 243 text m^3text/s.$$
This is equivalent to the flow of the Tiber river at Rome.
4
To put this into perspective: That is ~870km/h it is already 70% of Mach1/Speed of sound in air. If you jump off a plane the terminal velocity is about 60 m/s, this will hit you a lot harder. The power of the jet will hit like a full-blown tsunami and devastate most things in its path.
– Falco
Nov 20 at 10:27
4
@Falco It is 70% of speed of sound in air, but it is about 16% of speed of sound in water, so kingledion's assertion that the speed is much less than the speed of sound is correct. "The power of the jet will hit like a full-blown tsunami" - err, I think you vastly underestimated how dangerous the water will be. It is moving at roughly the speed from a black-powder musket, and it is a lot heavier than a musket ball.
– Martin Bonner
Nov 20 at 13:17
@MartinBonner Yeah, I meant to put that in the post but looks like I forgot. Mach number of fluid flow is relative to the speed of sound in the fluid.
– kingledion
Nov 20 at 13:37
@MartinBonner I don't know about "heavier" since the water is not as dense as a musket ball or stone flung from a catapult. Water Jet Cutters operate at an order of magnitude higher MPa so this water Jet will probably not cut through stone or steel, but will probably destroy a castle wall? I would be interested if one could calculate the destructive power comperatively? (Maybe N/cm² ?)
– Falco
Nov 20 at 13:38
2
Obligatory: this breaks conservation of energy in a BIG way. Since it hasn't been said yet.
– MindS1
Nov 20 at 13:47
|
show 4 more comments
up vote
11
down vote
This is easy. Just use Bernoulli equation. For such situation, it is like this water is falling from $3 , mathrmkm .$
$$
V_textexit
= sqrt2 H g
= sqrt2 times 3000 times 9.81
= 242.61 , fracmathrmmmathrms
$$
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
20
down vote
accepted
Pressure from depth
Hydrostatic pressure is the pressure felt due to the weight of things above it. The pressure at any depth in the ocean can be calculated by the equation for hydrostatic pressure:
$$p - p_0 = rho gh.$$
Here, $p_0$ is atmospheric pressure, and $p$ is pressure at the desired depth. The density of the fluid in the ocean is $rho$, $g$ is the acceleration due to gravity, and $h$ is the height of the column of fluid.
The density of water changes slightly with temperature, and even more slightly with pressure. We will assume a standard value of 1030 kg/m$^3$, which is accurate enough to three significant digits.
$$beginalignp &= 1030text kg/m^3cdot9.81text m/s^2cdot3000text m + 101000text Pa\
&=30.4 text MPaendalign$$
Flow velocity from pressure
Bernoulli's equation governs incompressible flow of fluids at a low Mach number. Since our flow will be well below the speed of sound (as we'll see) and since we've already made an incompressibility assumption by using constant density in the last equation, we can use Bernoulli's equation here. Bernoulli's equation is
$$c = fracv^22 + gz + fracprho$$
where $c$ is a constant, $v$ is the velocity of fluid flow, $z$ is elevation above reference, and $g$, $p$, and $rho$ are as before.
The constant can be factored out of the equation by rewriting the equation in terms of total head, which has units of meters. Before we re-write, we will cancel out $z$ as zero. You are asking for flow through a portal with no depth, there is no net elevation change between the pressure and low pressure zones. The energy head equation is
$$H = fracprho g+fracv^22g.$$
For the zero-velocity situation, i.e. on the ocean side of the portal, we set
$$H = fracp_Orho g.$$
On the atmosphere side of the portal, we set
$$H = fracp_arho g+fracv^22g.$$
Now we can set these two quantities equal to each other to solve for the velocity of the fluid flowing through the portal.
$$beginalignfracp_Orho g &= fracp_arho g + fracv^22g\
frac30400000text Pa1030text kg/m^3cdot9.81text m/s^2 &= frac101000text Pa1030text kg/m^3cdot9.81text m/s^2+fracv^22cdot9.81text m/s^2\
v^2 &= 2cdot9.81cdotleft(frac30400000010100-frac10100010100right)text m^2text/s^2\
v&= 243 text m/s
endalign$$
Volumetric flow from flow velocity
Volumetric flow is expressd as
$$dotV = vA,$$ where $A$ is the area of the portal. Sinc $A = 1text m^2$, we have
$$dotV = 243 text m^3text/s.$$
This is equivalent to the flow of the Tiber river at Rome.
4
To put this into perspective: That is ~870km/h it is already 70% of Mach1/Speed of sound in air. If you jump off a plane the terminal velocity is about 60 m/s, this will hit you a lot harder. The power of the jet will hit like a full-blown tsunami and devastate most things in its path.
– Falco
Nov 20 at 10:27
4
@Falco It is 70% of speed of sound in air, but it is about 16% of speed of sound in water, so kingledion's assertion that the speed is much less than the speed of sound is correct. "The power of the jet will hit like a full-blown tsunami" - err, I think you vastly underestimated how dangerous the water will be. It is moving at roughly the speed from a black-powder musket, and it is a lot heavier than a musket ball.
– Martin Bonner
Nov 20 at 13:17
@MartinBonner Yeah, I meant to put that in the post but looks like I forgot. Mach number of fluid flow is relative to the speed of sound in the fluid.
– kingledion
Nov 20 at 13:37
@MartinBonner I don't know about "heavier" since the water is not as dense as a musket ball or stone flung from a catapult. Water Jet Cutters operate at an order of magnitude higher MPa so this water Jet will probably not cut through stone or steel, but will probably destroy a castle wall? I would be interested if one could calculate the destructive power comperatively? (Maybe N/cm² ?)
– Falco
Nov 20 at 13:38
2
Obligatory: this breaks conservation of energy in a BIG way. Since it hasn't been said yet.
– MindS1
Nov 20 at 13:47
|
show 4 more comments
up vote
20
down vote
accepted
Pressure from depth
Hydrostatic pressure is the pressure felt due to the weight of things above it. The pressure at any depth in the ocean can be calculated by the equation for hydrostatic pressure:
$$p - p_0 = rho gh.$$
Here, $p_0$ is atmospheric pressure, and $p$ is pressure at the desired depth. The density of the fluid in the ocean is $rho$, $g$ is the acceleration due to gravity, and $h$ is the height of the column of fluid.
The density of water changes slightly with temperature, and even more slightly with pressure. We will assume a standard value of 1030 kg/m$^3$, which is accurate enough to three significant digits.
$$beginalignp &= 1030text kg/m^3cdot9.81text m/s^2cdot3000text m + 101000text Pa\
&=30.4 text MPaendalign$$
Flow velocity from pressure
Bernoulli's equation governs incompressible flow of fluids at a low Mach number. Since our flow will be well below the speed of sound (as we'll see) and since we've already made an incompressibility assumption by using constant density in the last equation, we can use Bernoulli's equation here. Bernoulli's equation is
$$c = fracv^22 + gz + fracprho$$
where $c$ is a constant, $v$ is the velocity of fluid flow, $z$ is elevation above reference, and $g$, $p$, and $rho$ are as before.
The constant can be factored out of the equation by rewriting the equation in terms of total head, which has units of meters. Before we re-write, we will cancel out $z$ as zero. You are asking for flow through a portal with no depth, there is no net elevation change between the pressure and low pressure zones. The energy head equation is
$$H = fracprho g+fracv^22g.$$
For the zero-velocity situation, i.e. on the ocean side of the portal, we set
$$H = fracp_Orho g.$$
On the atmosphere side of the portal, we set
$$H = fracp_arho g+fracv^22g.$$
Now we can set these two quantities equal to each other to solve for the velocity of the fluid flowing through the portal.
$$beginalignfracp_Orho g &= fracp_arho g + fracv^22g\
frac30400000text Pa1030text kg/m^3cdot9.81text m/s^2 &= frac101000text Pa1030text kg/m^3cdot9.81text m/s^2+fracv^22cdot9.81text m/s^2\
v^2 &= 2cdot9.81cdotleft(frac30400000010100-frac10100010100right)text m^2text/s^2\
v&= 243 text m/s
endalign$$
Volumetric flow from flow velocity
Volumetric flow is expressd as
$$dotV = vA,$$ where $A$ is the area of the portal. Sinc $A = 1text m^2$, we have
$$dotV = 243 text m^3text/s.$$
This is equivalent to the flow of the Tiber river at Rome.
4
To put this into perspective: That is ~870km/h it is already 70% of Mach1/Speed of sound in air. If you jump off a plane the terminal velocity is about 60 m/s, this will hit you a lot harder. The power of the jet will hit like a full-blown tsunami and devastate most things in its path.
– Falco
Nov 20 at 10:27
4
@Falco It is 70% of speed of sound in air, but it is about 16% of speed of sound in water, so kingledion's assertion that the speed is much less than the speed of sound is correct. "The power of the jet will hit like a full-blown tsunami" - err, I think you vastly underestimated how dangerous the water will be. It is moving at roughly the speed from a black-powder musket, and it is a lot heavier than a musket ball.
– Martin Bonner
Nov 20 at 13:17
@MartinBonner Yeah, I meant to put that in the post but looks like I forgot. Mach number of fluid flow is relative to the speed of sound in the fluid.
– kingledion
Nov 20 at 13:37
@MartinBonner I don't know about "heavier" since the water is not as dense as a musket ball or stone flung from a catapult. Water Jet Cutters operate at an order of magnitude higher MPa so this water Jet will probably not cut through stone or steel, but will probably destroy a castle wall? I would be interested if one could calculate the destructive power comperatively? (Maybe N/cm² ?)
– Falco
Nov 20 at 13:38
2
Obligatory: this breaks conservation of energy in a BIG way. Since it hasn't been said yet.
– MindS1
Nov 20 at 13:47
|
show 4 more comments
up vote
20
down vote
accepted
up vote
20
down vote
accepted
Pressure from depth
Hydrostatic pressure is the pressure felt due to the weight of things above it. The pressure at any depth in the ocean can be calculated by the equation for hydrostatic pressure:
$$p - p_0 = rho gh.$$
Here, $p_0$ is atmospheric pressure, and $p$ is pressure at the desired depth. The density of the fluid in the ocean is $rho$, $g$ is the acceleration due to gravity, and $h$ is the height of the column of fluid.
The density of water changes slightly with temperature, and even more slightly with pressure. We will assume a standard value of 1030 kg/m$^3$, which is accurate enough to three significant digits.
$$beginalignp &= 1030text kg/m^3cdot9.81text m/s^2cdot3000text m + 101000text Pa\
&=30.4 text MPaendalign$$
Flow velocity from pressure
Bernoulli's equation governs incompressible flow of fluids at a low Mach number. Since our flow will be well below the speed of sound (as we'll see) and since we've already made an incompressibility assumption by using constant density in the last equation, we can use Bernoulli's equation here. Bernoulli's equation is
$$c = fracv^22 + gz + fracprho$$
where $c$ is a constant, $v$ is the velocity of fluid flow, $z$ is elevation above reference, and $g$, $p$, and $rho$ are as before.
The constant can be factored out of the equation by rewriting the equation in terms of total head, which has units of meters. Before we re-write, we will cancel out $z$ as zero. You are asking for flow through a portal with no depth, there is no net elevation change between the pressure and low pressure zones. The energy head equation is
$$H = fracprho g+fracv^22g.$$
For the zero-velocity situation, i.e. on the ocean side of the portal, we set
$$H = fracp_Orho g.$$
On the atmosphere side of the portal, we set
$$H = fracp_arho g+fracv^22g.$$
Now we can set these two quantities equal to each other to solve for the velocity of the fluid flowing through the portal.
$$beginalignfracp_Orho g &= fracp_arho g + fracv^22g\
frac30400000text Pa1030text kg/m^3cdot9.81text m/s^2 &= frac101000text Pa1030text kg/m^3cdot9.81text m/s^2+fracv^22cdot9.81text m/s^2\
v^2 &= 2cdot9.81cdotleft(frac30400000010100-frac10100010100right)text m^2text/s^2\
v&= 243 text m/s
endalign$$
Volumetric flow from flow velocity
Volumetric flow is expressd as
$$dotV = vA,$$ where $A$ is the area of the portal. Sinc $A = 1text m^2$, we have
$$dotV = 243 text m^3text/s.$$
This is equivalent to the flow of the Tiber river at Rome.
Pressure from depth
Hydrostatic pressure is the pressure felt due to the weight of things above it. The pressure at any depth in the ocean can be calculated by the equation for hydrostatic pressure:
$$p - p_0 = rho gh.$$
Here, $p_0$ is atmospheric pressure, and $p$ is pressure at the desired depth. The density of the fluid in the ocean is $rho$, $g$ is the acceleration due to gravity, and $h$ is the height of the column of fluid.
The density of water changes slightly with temperature, and even more slightly with pressure. We will assume a standard value of 1030 kg/m$^3$, which is accurate enough to three significant digits.
$$beginalignp &= 1030text kg/m^3cdot9.81text m/s^2cdot3000text m + 101000text Pa\
&=30.4 text MPaendalign$$
Flow velocity from pressure
Bernoulli's equation governs incompressible flow of fluids at a low Mach number. Since our flow will be well below the speed of sound (as we'll see) and since we've already made an incompressibility assumption by using constant density in the last equation, we can use Bernoulli's equation here. Bernoulli's equation is
$$c = fracv^22 + gz + fracprho$$
where $c$ is a constant, $v$ is the velocity of fluid flow, $z$ is elevation above reference, and $g$, $p$, and $rho$ are as before.
The constant can be factored out of the equation by rewriting the equation in terms of total head, which has units of meters. Before we re-write, we will cancel out $z$ as zero. You are asking for flow through a portal with no depth, there is no net elevation change between the pressure and low pressure zones. The energy head equation is
$$H = fracprho g+fracv^22g.$$
For the zero-velocity situation, i.e. on the ocean side of the portal, we set
$$H = fracp_Orho g.$$
On the atmosphere side of the portal, we set
$$H = fracp_arho g+fracv^22g.$$
Now we can set these two quantities equal to each other to solve for the velocity of the fluid flowing through the portal.
$$beginalignfracp_Orho g &= fracp_arho g + fracv^22g\
frac30400000text Pa1030text kg/m^3cdot9.81text m/s^2 &= frac101000text Pa1030text kg/m^3cdot9.81text m/s^2+fracv^22cdot9.81text m/s^2\
v^2 &= 2cdot9.81cdotleft(frac30400000010100-frac10100010100right)text m^2text/s^2\
v&= 243 text m/s
endalign$$
Volumetric flow from flow velocity
Volumetric flow is expressd as
$$dotV = vA,$$ where $A$ is the area of the portal. Sinc $A = 1text m^2$, we have
$$dotV = 243 text m^3text/s.$$
This is equivalent to the flow of the Tiber river at Rome.
edited Nov 20 at 3:50
Davislor
2,741712
2,741712
answered Nov 20 at 1:59
kingledion
71k24237414
71k24237414
4
To put this into perspective: That is ~870km/h it is already 70% of Mach1/Speed of sound in air. If you jump off a plane the terminal velocity is about 60 m/s, this will hit you a lot harder. The power of the jet will hit like a full-blown tsunami and devastate most things in its path.
– Falco
Nov 20 at 10:27
4
@Falco It is 70% of speed of sound in air, but it is about 16% of speed of sound in water, so kingledion's assertion that the speed is much less than the speed of sound is correct. "The power of the jet will hit like a full-blown tsunami" - err, I think you vastly underestimated how dangerous the water will be. It is moving at roughly the speed from a black-powder musket, and it is a lot heavier than a musket ball.
– Martin Bonner
Nov 20 at 13:17
@MartinBonner Yeah, I meant to put that in the post but looks like I forgot. Mach number of fluid flow is relative to the speed of sound in the fluid.
– kingledion
Nov 20 at 13:37
@MartinBonner I don't know about "heavier" since the water is not as dense as a musket ball or stone flung from a catapult. Water Jet Cutters operate at an order of magnitude higher MPa so this water Jet will probably not cut through stone or steel, but will probably destroy a castle wall? I would be interested if one could calculate the destructive power comperatively? (Maybe N/cm² ?)
– Falco
Nov 20 at 13:38
2
Obligatory: this breaks conservation of energy in a BIG way. Since it hasn't been said yet.
– MindS1
Nov 20 at 13:47
|
show 4 more comments
4
To put this into perspective: That is ~870km/h it is already 70% of Mach1/Speed of sound in air. If you jump off a plane the terminal velocity is about 60 m/s, this will hit you a lot harder. The power of the jet will hit like a full-blown tsunami and devastate most things in its path.
– Falco
Nov 20 at 10:27
4
@Falco It is 70% of speed of sound in air, but it is about 16% of speed of sound in water, so kingledion's assertion that the speed is much less than the speed of sound is correct. "The power of the jet will hit like a full-blown tsunami" - err, I think you vastly underestimated how dangerous the water will be. It is moving at roughly the speed from a black-powder musket, and it is a lot heavier than a musket ball.
– Martin Bonner
Nov 20 at 13:17
@MartinBonner Yeah, I meant to put that in the post but looks like I forgot. Mach number of fluid flow is relative to the speed of sound in the fluid.
– kingledion
Nov 20 at 13:37
@MartinBonner I don't know about "heavier" since the water is not as dense as a musket ball or stone flung from a catapult. Water Jet Cutters operate at an order of magnitude higher MPa so this water Jet will probably not cut through stone or steel, but will probably destroy a castle wall? I would be interested if one could calculate the destructive power comperatively? (Maybe N/cm² ?)
– Falco
Nov 20 at 13:38
2
Obligatory: this breaks conservation of energy in a BIG way. Since it hasn't been said yet.
– MindS1
Nov 20 at 13:47
4
4
To put this into perspective: That is ~870km/h it is already 70% of Mach1/Speed of sound in air. If you jump off a plane the terminal velocity is about 60 m/s, this will hit you a lot harder. The power of the jet will hit like a full-blown tsunami and devastate most things in its path.
– Falco
Nov 20 at 10:27
To put this into perspective: That is ~870km/h it is already 70% of Mach1/Speed of sound in air. If you jump off a plane the terminal velocity is about 60 m/s, this will hit you a lot harder. The power of the jet will hit like a full-blown tsunami and devastate most things in its path.
– Falco
Nov 20 at 10:27
4
4
@Falco It is 70% of speed of sound in air, but it is about 16% of speed of sound in water, so kingledion's assertion that the speed is much less than the speed of sound is correct. "The power of the jet will hit like a full-blown tsunami" - err, I think you vastly underestimated how dangerous the water will be. It is moving at roughly the speed from a black-powder musket, and it is a lot heavier than a musket ball.
– Martin Bonner
Nov 20 at 13:17
@Falco It is 70% of speed of sound in air, but it is about 16% of speed of sound in water, so kingledion's assertion that the speed is much less than the speed of sound is correct. "The power of the jet will hit like a full-blown tsunami" - err, I think you vastly underestimated how dangerous the water will be. It is moving at roughly the speed from a black-powder musket, and it is a lot heavier than a musket ball.
– Martin Bonner
Nov 20 at 13:17
@MartinBonner Yeah, I meant to put that in the post but looks like I forgot. Mach number of fluid flow is relative to the speed of sound in the fluid.
– kingledion
Nov 20 at 13:37
@MartinBonner Yeah, I meant to put that in the post but looks like I forgot. Mach number of fluid flow is relative to the speed of sound in the fluid.
– kingledion
Nov 20 at 13:37
@MartinBonner I don't know about "heavier" since the water is not as dense as a musket ball or stone flung from a catapult. Water Jet Cutters operate at an order of magnitude higher MPa so this water Jet will probably not cut through stone or steel, but will probably destroy a castle wall? I would be interested if one could calculate the destructive power comperatively? (Maybe N/cm² ?)
– Falco
Nov 20 at 13:38
@MartinBonner I don't know about "heavier" since the water is not as dense as a musket ball or stone flung from a catapult. Water Jet Cutters operate at an order of magnitude higher MPa so this water Jet will probably not cut through stone or steel, but will probably destroy a castle wall? I would be interested if one could calculate the destructive power comperatively? (Maybe N/cm² ?)
– Falco
Nov 20 at 13:38
2
2
Obligatory: this breaks conservation of energy in a BIG way. Since it hasn't been said yet.
– MindS1
Nov 20 at 13:47
Obligatory: this breaks conservation of energy in a BIG way. Since it hasn't been said yet.
– MindS1
Nov 20 at 13:47
|
show 4 more comments
up vote
11
down vote
This is easy. Just use Bernoulli equation. For such situation, it is like this water is falling from $3 , mathrmkm .$
$$
V_textexit
= sqrt2 H g
= sqrt2 times 3000 times 9.81
= 242.61 , fracmathrmmmathrms
$$
add a comment |
up vote
11
down vote
This is easy. Just use Bernoulli equation. For such situation, it is like this water is falling from $3 , mathrmkm .$
$$
V_textexit
= sqrt2 H g
= sqrt2 times 3000 times 9.81
= 242.61 , fracmathrmmmathrms
$$
add a comment |
up vote
11
down vote
up vote
11
down vote
This is easy. Just use Bernoulli equation. For such situation, it is like this water is falling from $3 , mathrmkm .$
$$
V_textexit
= sqrt2 H g
= sqrt2 times 3000 times 9.81
= 242.61 , fracmathrmmmathrms
$$
This is easy. Just use Bernoulli equation. For such situation, it is like this water is falling from $3 , mathrmkm .$
$$
V_textexit
= sqrt2 H g
= sqrt2 times 3000 times 9.81
= 242.61 , fracmathrmmmathrms
$$
edited Nov 20 at 6:30
Nat
4371412
4371412
answered Nov 20 at 1:29
Artemijs Danilovs
8028
8028
add a comment |
add a comment |
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6
Obligatory XKCD
– Cort Ammon
Nov 20 at 7:31
4
Bit of a bigger hole, but obligatory What If XKCD
– CalvT
Nov 20 at 10:10
There would be no high pressure water jet. The portal acts on water particles with force enough to balance the pressure. The second principle of teleportation is that energy required for a body to enter a portal is equal of resulting gain of its potential energy - thus the energy conservation principle is not being violated.
– abukaj
2 days ago