### Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2099851 times)

#### Cinder

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #840 on: 02/19/2015 02:49 PM »
EDIT: Apparently the problem is with the way that Dropbox posts the image in a webpage: the dropbox link does not show like other links
It is probably simplest to do as elsewhere on the forum: attach/upload the pictures directly.  Especially now that the effort has probably snowballed for good.
The pork must flow.

#### Star One

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #841 on: 02/19/2015 03:59 PM »
Can I just add to this thread that though my understanding barely scratches the surface of this topic that I consider it a great privilege to be able to sit in on the discussion of far more learned minds than mine.

#### FuturePass

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #842 on: 02/19/2015 05:56 PM »
Isn't frustum a misnomer since frustum refers to a cone, not a four-sided structure...?

Is the frustum-under-test (fut) just a truncated pyramid structure?

Scaling of the frustron could be done
by dimension (monolith) or by array of smaller units.
The following is a raw propulsion calculation only
and does not address or include power, weight, heat transfer
and other system engineering issues.

Imagine a frustum approximately the size of the Giza pyramid with dimensions is

(b x h) 146 m x 230 m  (450 ft x 750 ft).

If the current frustum is approximately 0.146 m x 0.230 m ,
then scaling factor for the frustum volume to the full pyramid
can be grossly calculated by approximately 146 / 0.146 or about 1000 per dimension.

For 100 mN thrust, the total scale factor is

(l w h) == 1000 x 1000 x 1000 = 1 B scaling factor.

If the a frustum produces 100 mN thrust,
a Giza size structure  might produce thrust of 100 million Newtons.

In comparison, a Saturn V First stage
produces approximately 34 kN (7,648,000 lbf)

If we scale up by a only a factor of 10 or 100,
we have respectively thrust maximums of 100 N or 100 kN.

YMMV

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #843 on: 02/19/2015 06:05 PM »
Isn't frustum a misnomer since frustum refers to a cone, not a four-sided structure...?

Is the frustum-under-test (fut) just a truncated pyramid structure?

...

It is not a misnomer, what is called the "frustum" by NASA's Brady et.al. is a frustum of a cone, or a truncated cone.  It is not a truncated pyramid, as shown by the images below for NASA's truncated cone (ditto for Shawyer's EM Drive in the UK and Prof. Juan Yang's in China)

Frustum:  "the portion of a cone or pyramid that remains after its upper part has been cut off by a plane parallel to its base, or that is intercepted between two such planes"
« Last Edit: 02/19/2015 06:25 PM by Rodal »

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #844 on: 02/19/2015 06:19 PM »
...

If the a frustum produces 100 mN thrust,
a Giza size structure  might produce thrust of 100 million Newtons.

In comparison, a Saturn V First stage
produces approximately 34 kN (7,648,000 lbf)

If we scale up by a only a factor of 10 or 100,
we have respectively thrust maximums of 100 N or 100 kN.
...
The thrust of the EM Drive (if it is not an artifact, and if indeed it can be used for space propulsion) it is not expected to scale geometrically.  On the contrary, (as discussed previously in this thread), the larger the diameter, the lower the natural frequencies of the first few modes.  A significantly larger EM Drive truncated cone would result in either very low natural frequencies for the first few modes, or if one would attempt to excite the EM Drive in the GHz range, these natural frequencies would correspond to very high mode shapes that would be bunched up together in the frequency spectrum and it would be even much more difficult to keep the EM Drive in resonance with a particular mode shape.  Also, very high natural frequency mode shapes are extremely difficult to calculate accurately (even with the exact solution, and almost hopeless with the Finite Element method because of difficult issues associated with ill-conditioning in inverting the matrix for very large eigenvalues).

What is envisioned (if it is not an artifact, and if indeed it can be used for space propulsion) , rather than a very large EM Drive, is to maximize the thrust of the EM Drive (perhaps using superconductivity, and/or high magnetic permeability materials for the big flat end, as well as much better, anisotropic, dielectric) and to use a number of EM Drives to achieve a large overall thrust.

Unlike liquid propellant rocket engines, there are no issues of fuels and oxidizers hydraulic lines,  pumps, injectors, combustion instability, ignition, hydraulic pressure, etc., associated with using a large number of EM Drives, of course, particularly if ambient temperature EM Drives are used (and superconducting low temperature solutions can be avoided).
« Last Edit: 02/19/2015 06:47 PM by Rodal »

#### Mulletron

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #845 on: 02/19/2015 06:21 PM »
Not really my expertise field.............
Welcome to the group. This is very much a multidisciplinary effort. What are you good at?
Challenge your preconceptions, or they will challenge you. - Velik

#### Notsosureofit

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #846 on: 02/19/2015 06:47 PM »

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #847 on: 02/19/2015 06:49 PM »
« Last Edit: 02/19/2015 06:51 PM by Rodal »

#### TescoBag

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #848 on: 02/19/2015 06:50 PM »
...

If the a frustum produces 100 mN thrust,
a Giza size structure  might produce thrust of 100 million Newtons.

In comparison, a Saturn V First stage
produces approximately 34 kN (7,648,000 lbf)

If we scale up by a only a factor of 10 or 100,
we have respectively thrust maximums of 100 N or 100 kN.
...
The thrust of the EM Drive (if it is not an artifact, and if indeed it can be used for space propulsion) it is not expected to scale geometrically.  On the contrary, (as discussed previously in this thread), the larger the diameter, the lower the natural frequencies of the first few modes.  A significantly larger EM Drive truncated cone would result in either very low natural frequencies for the first few modes, or if one would attempt to excite the EM Drive in the GHz range, these natural frequencies would correspond to very high mode shapes that would be bunched up together in the frequency spectrum and it would be even much more difficult to keep the EM Drive in resonance with a particular mode shape.  Also, very high natural frequency mode shapes are extremely difficult to calculate accurately (even with the exact solution, and almost hopeless with the Finite Element method because of difficult issues associated with ill-conditioning in inverting the matrix for very large eigenvalues).

What is envisioned (if it is not an artifact, and if indeed it can be used for space propulsion) , rather than a very large EM Drive, is to maximize the thrust of the EM Drive (perhaps using superconductivity, and/or high magnetic permeability materials for the big flat end, as well as much better, anisotropic, dielectric) and to use a number of EM Drives to achieve a large overall thrust.

Unlike liquid propellant rocket engines, there are no issues of fuels and oxidizers hydraulic lines,  pumps, injectors, combustion instability, ignition, hydraulic pressure, etc., associated with using a large number of EM Drives, of course, particularly if ambient temperature EM Drives are used (and superconducting low temperature solutions are avoided).

Hi,

Just want to say that I am enjoying this thread immensely even though a lot of the science is a bit above my pay grade!

If the thrust is not an artifact of the experiment, in theory what level of thrust are we expecting in the best circumstances?

#### aceshigh

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #849 on: 02/19/2015 06:52 PM »
A question... is the Q-Thruster that was being worked by EagleWorks Lab similar to the EM Drive they tested? Are them completely different things with different principles? I have the vague notion of seeing a photo of it long ago (while the main subject of the article was in fact Dr White's Warp Drive experiments) and I donīt remember it having a cone similar to Shawyer's EM Drive, so I guess they are totally different principles? I wonder if the former is still being pursued? If it is "considered" an EM Drive? Maybe Paul March can clear this up (if noone else knows the answer)?

#### Star One

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #850 on: 02/19/2015 06:52 PM »
Would one practical use, if they do work, be a satellite with clusters of EM drives on different axis used for station keeping?

Of how much practical use would they be in reality for interplanetary probes.
« Last Edit: 02/19/2015 06:59 PM by Star One »

#### Mulletron

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #851 on: 02/19/2015 06:56 PM »
« Last Edit: 02/19/2015 06:59 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #852 on: 02/19/2015 06:58 PM »
.
The thrust of the EM Drive (if it is not an artifact, and if indeed it can be used for space propulsion) it is not expected to scale geometrically.  On the contrary, (as discussed previously in this thread), the larger the diameter, the lower the natural frequencies of the first few modes.  A significantly larger EM Drive truncated cone would result in either very low natural frequencies for the first few modes, or if one would attempt to excite the EM Drive in the GHz range, these natural frequencies would correspond to very high mode shapes that would be bunched up together in the frequency spectrum and it would be even much more difficult to keep the EM Drive in resonance with a particular mode shape.  Also, very high natural frequency mode shapes are extremely difficult to calculate accurately (even with the exact solution, and almost hopeless with the Finite Element method because of difficult issues associated with ill-conditioning in inverting the matrix for very large eigenvalues).

What is envisioned (if it is not an artifact, and if indeed it can be used for space propulsion) , rather than a very large EM Drive, is to maximize the thrust of the EM Drive (perhaps using superconductivity, and/or high magnetic permeability materials for the big flat end, as well as much better, anisotropic, dielectric) and to use a number of EM Drives to achieve a large overall thrust.

Unlike liquid propellant rocket engines, there are no issues of fuels and oxidizers hydraulic lines,  pumps, injectors, combustion instability, ignition, hydraulic pressure, etc., associated with using a large number of EM Drives, of course, particularly if ambient temperature EM Drives are used (and superconducting low temperature solutions are avoided).

Hi,

Just want to say that I am enjoying this thread immensely even though a lot of the science is a bit above my pay grade!

If the thrust is not an artifact of the experiment, in theory what level of thrust are we expecting in the best circumstances?

Welcome to the forum.

There is no unifying theory yet.  Some expect it to be an experimental artifact.  Some propose ambitious crewed missions to the outer planets. Dr. White at NASA proposed the following mission parameters as feasible

2MW NEP (90t spacecraft) Crewed Titan/Enceladus Mission with 0.4N/kWe thrust to power

9 month trip each way

P= 2000 kW

« Last Edit: 02/19/2015 07:10 PM by Rodal »

#### aceshigh

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #853 on: 02/19/2015 07:07 PM »
those mission parameters presupposed electrical power from solar panels? I guess that some good fission or fusion reactors (whenever fusion is available) would allow the addition of even more EM Drives and cut that mission time several times.

#### Star One

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #854 on: 02/19/2015 07:08 PM »
This is what confusing about this as some proponents of the technology talk of grand projects others speak of far more modest expectations and to the layperson that's rather confusing.
« Last Edit: 02/19/2015 07:08 PM by Star One »

#### TescoBag

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #855 on: 02/19/2015 07:12 PM »
This is what confusing about this as some proponents of the technology talk of grand projects others speak of far more modest expectations and to the layperson that's rather confusing.

I would think that the larger, more optimistic predictions are relying on technology that hasn't been developed yet but is in theory possible.

#### RotoSequence

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #856 on: 02/19/2015 07:17 PM »
This is what confusing about this as some proponents of the technology talk of grand projects others speak of far more modest expectations and to the layperson that's rather confusing.

There's a lot of uncertainty about how scalable these drives will be (assuming they work). It hasn't proven easy to create a consistent dataset with existing test articles and equipment, and there's little knowledge about how much potential EM drives have.

One order of magnitude improvement will enable an interesting subset of station keeping thrusters and low-acceleration drives. Two orders of magnitude yields what we see in the above the Saturnian mission profile. Three or more orders of magnitude would make rockets obsolete.

#### Star One

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #857 on: 02/19/2015 07:19 PM »
This is what confusing about this as some proponents of the technology talk of grand projects others speak of far more modest expectations and to the layperson that's rather confusing.

I would think that the larger, more optimistic predictions are relying on technology that hasn't been developed yet but is in theory possible.

Good point. The other point of confusion is this purely a technology if it works that is only useful outside the atmosphere because of the conditions of its operation. I've read it couldn't actual get anything on its own off the ground, so it's of no use for a making a launch vehicle. We aren't going to get George Jetson getting in his flying car and nipping off to the moon.
« Last Edit: 02/19/2015 07:21 PM by Star One »

#### TescoBag

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #858 on: 02/19/2015 07:29 PM »
This is what confusing about this as some proponents of the technology talk of grand projects others speak of far more modest expectations and to the layperson that's rather confusing.

I would think that the larger, more optimistic predictions are relying on technology that hasn't been developed yet but is in theory possible.

Good point. The other point of confusion is this purely a technology if it works that is only useful outside the atmosphere because of the conditions of its operation. I've read it couldn't actual get anything on its own off the ground, so it's of no use for a making a launch vehicle. We aren't going to get George Jetson getting in his flying car and nipping off to the moon.

Shawyer has seemed convinced that this drive is able to replace commercial airliner engines etc. Obviously as he is the main proponent of the drive so this might be taken with a pinch of salt or two but if the drive is proven to be real he definitely seems to be ahead of the curve with the technology.

#### Mulletron

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##### Re: EM Drive Developments - related to space flight applications - Thread 2
« Reply #859 on: 02/19/2015 07:34 PM »
A question... is the Q-Thruster that was being worked by EagleWorks Lab similar to the EM Drive they tested? Are them completely different things with different principles? I have the vague notion of seeing a photo of it long ago (while the main subject of the article was in fact Dr White's Warp Drive experiments) and I donīt remember it having a cone similar to Shawyer's EM Drive, so I guess they are totally different principles? I wonder if the former is still being pursued? If it is "considered" an EM Drive? Maybe Paul March can clear this up (if noone else knows the answer)?

It appears that when METs, MLT, SFEs, Cannaes and Emdrives go through the doors of Eagleworks, they get rolled into the QVPT conjecture. In reality, they come from different sources, different inventors with different theories of operation. Dr. White, IMHO is right to try and unify these different types of "thrusters" under the same paradigm. I think they are all unified too under the same interaction, maybe not QVPT per se, but they share the QV as a common means of interaction.