Jump to content

Interview regarding M1A2 SEP v4 and question.


Recommended Posts

8 minutes ago, Battlefront.com said:

 

 

So... let's try to keep this thread better on track, eh?

Please tell me that pun was on purpose. :)

I was reading more about the upgrade and the meteorological suite piqued my interest. Seems the already amazing accuracy of the Abrams is going to get even better. I do wonder how useful the wind sensor is going to be though. I foresee trouble when the tank is moving, or facing the wrong way, or if it's damaged, or maybe even dirty, and the sensor info throws off the first shot before the gunner knows to dump it. Maybe its mountains out of molehills?

Link to post
Share on other sites
5 hours ago, HerrTom said:

Please tell me that pun was on purpose. :)

I was reading more about the upgrade and the meteorological suite piqued my interest. Seems the already amazing accuracy of the Abrams is going to get even better. I do wonder how useful the wind sensor is going to be though. I foresee trouble when the tank is moving, or facing the wrong way, or if it's damaged, or maybe even dirty, and the sensor info throws off the first shot before the gunner knows to dump it. Maybe its mountains out of molehills?

The wind sensor picks up atmospheric pressure. That gives density information. The density is critical to the drag profile.

As to winds being inaccurate while moving, that may not be true. If I have a wind sensor and a GPS, I can take the raw relative wind, subtract out the GPS movement, and come up with actual wind. Quite trivial.

I have NO idea if that's how it's done in tanks.

Link to post
Share on other sites
16 hours ago, c3k said:

The wind sensor picks up atmospheric pressure. That gives density information. The density is critical to the drag profile.

As to winds being inaccurate while moving, that may not be true. If I have a wind sensor and a GPS, I can take the raw relative wind, subtract out the GPS movement, and come up with actual wind. Quite trivial.

I have NO idea if that's how it's done in tanks.

A good point, though my biggest concern especially regarding movement is that the flowfield around moving objects is generally very chaotic.  I wonder whether you'd even be able to measure something akin to the wind in this:

vectra_velo_surf.gif

And that's a car, which is aerodynamically shaped.  Nothing compared to a big fat tank!  (I think this picture is colored according to velocity).

John, thanks for the information.  I guess it really doesn't cause significant enough problems if the Russians have been doing it for so long.  I've been trained on a modified Murphy's law: anything that can go wrong, will go wrong, at the worst possible time, and the worst possible way!  I mean, I see cold weather and a little rubber ring and think: that killed six people, but I guess military hardware operates in a different realm than I'm used to! :)

Link to post
Share on other sites
On 19/02/2017 at 5:35 PM, HerrTom said:

It's like Godwin's law, but for this Forum.  I'm sure it's Hitler in the WWII ones!

Here's another article I found about it.  Not sure if it's any more new info:

http://nationalinterest.org/blog/the-buzz/americas-once-future-tank-the-us-new-m1a2-sep-v4-super-18422

It's interesting that they're replacing the canister round with the M908 "Obstacle Reduction" high explosive round.  I guess CMBS' airburst rounds are becoming a standard-issue reality.

http://www.globalsecurity.org/military/systems/munitions/m908.htm

 

I've named it already  :-)

"Putler's Law". 

 

 

Link to post
Share on other sites
5 hours ago, HerrTom said:

A good point, though my biggest concern especially regarding movement is that the flowfield around moving objects is generally very chaotic.  I wonder whether you'd even be able to measure something akin to the wind in this:

vectra_velo_surf.gif

And that's a car, which is aerodynamically shaped.  Nothing compared to a big fat tank!  (I think this picture is colored according to velocity).

John, thanks for the information.  I guess it really doesn't cause significant enough problems if the Russians have been doing it for so long.  I've been trained on a modified Murphy's law: anything that can go wrong, will go wrong, at the worst possible time, and the worst possible way!  I mean, I see cold weather and a little rubber ring and think: that killed six people, but I guess military hardware operates in a different realm than I'm used to! :)

The turbulent layers in that image are between the car and road and behind the car. Put a mast on the roof of the car. It wouldn't take much height to get it into the freestream airflow.

A tank moves much more slowly than a car. Car manufacturers try to get laminar flow (reduce the turbulence), especially behind a car, in order to reduce drag and to improve fuel economy. (High performance cars also try to control downforce and eliminate body lift.) Car designers are very concerned with the colored areas in that image. Tank ballistic computers couldn't car less about what's happening under or behind the tank. ;)

Link to post
Share on other sites
4 hours ago, c3k said:

The turbulent layers in that image are between the car and road and behind the car. Put a mast on the roof of the car. It wouldn't take much height to get it into the freestream airflow.

A tank moves much more slowly than a car. Car manufacturers try to get laminar flow (reduce the turbulence), especially behind a car, in order to reduce drag and to improve fuel economy. (High performance cars also try to control downforce and eliminate body lift.) Car designers are very concerned with the colored areas in that image. Tank ballistic computers couldn't car less about what's happening under or behind the tank. ;)

The flow quickly transitions from laminar to turbulent somewhere on the forward section of the hood, but flow separation is the biggest problem.  You can see it in the car picture as the low-velocity wake behind the vehicle.  This causes vortex shedding which is a source of even more drag.  But you have a good point.

Further research tells me this sensor is on the roof, and has been since the 80s.  This particular one is on the M1A2, so I guess it's always been there?

http://j-tecassociates.com/military-tank-crosswind-sensor/

So mountains out of molehills indeed.  I guess I expected it to be more conformal to the tank body to reduce the chances of it getting damaged.

Link to post
Share on other sites
On ‎21‎/‎02‎/‎2017 at 6:31 AM, Battlefront.com said:

Any of you who have been here long enough, or been out on other Forums for any length of time, should know that it's pointless to try and debate someone who believes what is shown on Russian TV.  We go through the same process of "wahtaboutism" and "alternative facts" each and every time.  It doesn't matter how may times we go through this process... the world is flat because that's what Russian TV said.  Case closed.

It would be nice if we could keep on the topic of tanks in a tank thread on a military wargame forum.  But that makes some uncomfortable, so they distract with unrelated politics.  And so the downward spiral begins.

So... let's try to keep this thread better on track, eh?

Steve

You are your own forum's worst enemy.....Your second statement completely contradicts the political waffle in the first.

Maybe spend more time working on CM:FI and less in here ruining your own company's reputation?

Just a thought.  :mellow:

Link to post
Share on other sites
5 hours ago, Sgt.Squarehead said:

You are your own forum's worst enemy.....Your second statement completely contradicts the political waffle in the first.

As a Moderator it is my job to recognize patterns of behavior.  And oh boy, is there a pattern of behavior for me to recognize.

5 hours ago, Sgt.Squarehead said:

Maybe spend more time working on CM:FI and less in here ruining your own company's reputation?

Maybe you should spend less time trying to stir up trouble and more time playing the games? As for my company's reputation, I'm perfectly fine with what I say and how I say it.  Been doing it for 20 years, still here.

5 hours ago, Sgt.Squarehead said:

Just a thought.  :mellow:

And I have a thought.  Stop trying to provoke conflicts.  That is trolling and I'm going to give you a warning here as well as the other thread where you are doing it.

You've been warned.

Steve

Link to post
Share on other sites

Fair play Steve.....It is your manor after all and my comment was rather out of order.  

Not sure there's a pattern to my general behaviour, just to the posts that have drawn your attention recently, the majority of my posts are to be found in other, more productive threads TBH.....Sadly those kinds of threads often don't seem to receive as much attention as they possibly should.

 

Edited by Sgt.Squarehead
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...