The Venturi Effect and other possible solutions

[Brietta]

Today Barrier posted on another thread which had 'slipped' into the window discussion again.

Nope, I'm trying to fathom the open window which a half decent defence would question, but I doubt any prosecution would rely on it .This thread is about stranger abduction and evidence there of.
https://miscarriageofjustice.co/index.php?topic=12484.msg698271#msg698271

Which gave me pause for thought about forum discussions in the past which had either resolved questions or which at the least suggested explanation of events.

I am not a scientist but I did understand what those with  a greater understanding of physics had worked out regarding the trope of the "whoosh" of curtains.
Always a shame to lose information then have to go back to the drawing board for it - when it is already available on the forum.
So often these are discussed – then forgotten again as here.

One of these being the physics of the Venturi Effect on anything that flows – for example liquids such as water, and gases such as air.
Did You Know?
The ‘explosion’ of windows during a tornado is due to the Venturi effect. Because wind blowing at a high speed creates low pressure, the air inside the house rushes out to occupy this void.
https://sciencestruck.com/explanation-applications-of-venturi-effect

Kate McCann demonstrated in her account of events what happens when conditions are right for the Venturi Effect to occur.
We have all seen her describing pulling the bedroom door towards her which slammed!!!.  Some of us have mocked and laughed at her.  But physics prove her account.

[Wonderfulspam]

Today Barrier posted on another thread which had 'slipped' into the window discussion again.

Nope, I'm trying to fathom the open window which a half decent defence would question, but I doubt any prosecution would rely on it .This thread is about stranger abduction and evidence there of.
https://miscarriageofjustice.co/index.php?topic=12484.msg698271#msg698271

Which gave me pause for thought about forum discussions in the past which had either resolved questions or which at the least suggested explanation of events.

I am not a scientist but I did understand what those with  a greater understanding of physics had worked out regarding the trope of the "whoosh" of curtains.
Always a shame to lose information then have to go back to the drawing board for it - when it is already available on the forum.
So often these are discussed – then forgotten again as here.

One of these being the physics of the Venturi Effect on anything that flows – for example liquids such as water, and gases such as air.
Did You Know?
The ‘explosion’ of windows during a tornado is due to the Venturi effect. Because wind blowing at a high speed creates low pressure, the air inside the house rushes out to occupy this void.
https://sciencestruck.com/explanation-applications-of-venturi-effect

Kate McCann demonstrated in her account of events what happens when conditions are right for the Venturi Effect to occur.
We have all seen her describing pulling the bedroom door towards her which slammed!!!.  Some of us have mocked and laughed at her. But physics prove her account.

No, physics do not prove her account. Your opinion might be that it does, but that's not the same thing as actually proving her account I'm afraid.

[Brietta]

No, physics do not prove her account. Your opinion might be that it does, but that's not the same thing as actually proving her account I'm afraid.

You haven't disappointed my expectation that you would post your rather exotic opinions in an attempt to WUM your way through a thread set up to discuss serious scientific observations. 

       🤡 AND HERE YOU ARE 🤡

[Wonderfulspam]

You haven't disappointed my expectation that you would post your rather exotic opinions in an attempt to WUM your way through a thread set up to discuss serious scientific observations. 

       🤡 AND HERE YOU ARE 🤡

Sigh. I did try telling you before, if you stop making easily contestable statements & presenting your opinion as fact in your posts every time, I wouldn't feel compelled to reply.
If you'd have said physics supports Kate's account, rather than proves it, you might not have heard from me.

[Brietta]

Re: The whooshing curtains, net curtains or both?
http://miscarriageofjustice.co/index.php?PHPSESSID=dv5rq14n4fuh4s4mqau9lsmue5&topic=5477.msg197144#msg197144

Quote from: John on November 01, 2014, 09:00:51 PM
Mat looked into the kids bedroom a mere 30 minutes before Kate and he never reported open curtains and an open shutter.  So what changed?

Pegasus
During the 2130 check, the pressure in the lounge diner kitchen hall was normal atmospheric pressure, with a constant through draught coming in window and out kitchen vent.

Same during the first part of the 2200 check.

But there is a big change of scenario when the 2200 checker moves the door to almost closed, because this enables the through draught to slam the door shut.

Now suddenly the pressure in lounge diner kitchen hall drops from normal to negative because no air can enter apartment to replace air being sucked strongly up vent.

And then when the 2200 checker reopens the bedroom door, there is a single extra strong blast of air in through the window to bring the negative pressure in lounge etc back up to normal.

It was that one off blast of air which blew the curtains in.   So that explains the difference between the 2130 check and the 2200 check.
       
                                 ****        ****        ****        ****        ****

The opening post on this thread (The whooshing curtains, net curtains or both?) asks the question ~
"The way Kate describes the curtains billowing open though is surprising to me given they were floor length curtains in the photos... Not saying that couldn't happen just surprising..." Fair point and certainly one worth checking out particularly as it was an experience described by a material witness to the event.

I know that Rebelo on takeover of the case showed a great deal of interest in egress and ingress via the bedroom window ~ we've seen the photos.

What I don't know is if he entered into the science of the happening by asking the forensic science institute or other experts for an opinion on this very precise evidence.

[barrier]

Who ever pegasus is or was , were they in 5a with a barometer ?

[Venturi Swirl]

Who ever pegasus is or was , were they in 5a with a barometer ?

and yet there are many, many sceptics who know for a fact that the curtains could never have whooshed - were they all piled in there too, observing?

[Brietta]

Who ever pegasus is or was , were they in 5a with a barometer ?

Pegasus posted erudite and well thought out information on this forum on which s/he was a valued contributor and I think your question would have raised an eyebrow ~ quite simply because such an illogical non-sequitur was way beneath the standard of expected response.

Now back to the effect of the Venturi Effect.

Quite simply I do know that Kate was present in 5A and was able to describe the Venturi Effect perfectly.  Was there a requirement for a barometer to enable her to do that?
You've raised the question - perhaps you would explain your thoughts and enlighten the forum.

[Brietta]

and yet there are many, many sceptics who know for a fact that the curtains could never have whooshed - were they all piled in there too, observing?

The Venturi Effect is an explanation.

There was another myth associated with the window (do forgive me for missing out the lichen which photographic evidence dismissed).
Remember the bandwith taken up with the 'evidence' that it was impossible to raise the shutter and open the window from outside as described by the material witnesses.  We've seen that disproved as we watched the video of the window being opened after the shutter had been raised ~ from the outside.

[Venturi Swirl]

The Venturi Effect is an explanation.

There was another myth associated with the window (do forgive me for missing out the lichen which photographic evidence dismissed).
Remember the bandwith taken up with the 'evidence' that it was impossible to raise the shutter and open the window from outside as described by the material witnesses.  We've seen that disproved as we watched the video of the window being opened after the shutter had been raised ~ from the outside.

Given the level of discussion on here in the last few days in which we have examined whooshed curtains, the e-fits, the way doctors certainly behave in any given situation, etc surely it is only a matter of time before the subject of lichen and Kate's earrings are resurrected.  We haven't had Gerry swearing on the bus for a while either, any takers for that?  Yes, by golly, when you think about it the evidence that "the McCanns Murdered Maddie" sure does stack up!

[kizzy]

Re: The whooshing curtains, net curtains or both?
http://miscarriageofjustice.co/index.php?PHPSESSID=dv5rq14n4fuh4s4mqau9lsmue5&topic=5477.msg197144#msg197144

Quote from: John on November 01, 2014, 09:00:51 PM
Mat looked into the kids bedroom a mere 30 minutes before Kate and he never reported open curtains and an open shutter.  So what changed?

Pegasus
During the 2130 check, the pressure in the lounge diner kitchen hall was normal atmospheric pressure, with a constant through draught coming in window and out kitchen vent.

Same during the first part of the 2200 check.

But there is a big change of scenario when the 2200 checker moves the door to almost closed, because this enables the through draught to slam the door shut.

Now suddenly the pressure in lounge diner kitchen hall drops from normal to negative because no air can enter apartment to replace air being sucked strongly up vent.

And then when the 2200 checker reopens the bedroom door, there is a single extra strong blast of air in through the window to bring the negative pressure in lounge etc back up to normal.

It was that one off blast of air which blew the curtains in.   So that explains the difference between the 2130 check and the 2200 check.
       
                                 ****        ****        ****        ****        ****

The opening post on this thread (The whooshing curtains, net curtains or both?) asks the question ~
"The way Kate describes the curtains billowing open though is surprising to me given they were floor length curtains in the photos... Not saying that couldn't happen just surprising..." Fair point and certainly one worth checking out particularly as it was an experience described by a material witness to the event.

I know that Rebelo on takeover of the case showed a great deal of interest in egress and ingress via the bedroom window ~ we've seen the photos.

What I don't know is if he entered into the science of the happening by asking the forensic science institute or other experts for an opinion on this very precise evidence.

But there is a big change of scenario when the 2200 checker moves the door to almost closed, because this enables the through draught to slam the door shut


So why didn't this happen when she opened the patio door

[Lace]

But there is a big change of scenario when the 2200 checker moves the door to almost closed, because this enables the through draught to slam the door shut


So why didn't this happen when she opened the patio door

Maybe because there was no gust of wind when Kate came in through the patio door.    Amaral did say in his book it was windy at night.

[Wonderfulspam]

Maybe because there was no gust of wind when Kate came in through the patio door.    Amaral did say in his book it was windy at night.

Well you can never trust anything Amaral says, he's a convicted liar, so it was probably calm & windless night really.

[jassi]

Well you can never trust anything Amaral says, he's a convicted liar, so it was probably calm & windless night really.

 

[Brietta]

But there is a big change of scenario when the 2200 checker moves the door to almost closed, because this enables the through draught to slam the door shut


So why didn't this happen when she opened the patio door

I don't know.  I'm not a scientist.

I do know what the witness said in her statement correctly described what happens in such circumstances and I do know that a diagram illustrating the effect was posted on the forum at one time.
And if you are really interested the internet is full of them.

Slamming of doors by a draft
The slamming of doors due to a draft, is also due to the Venturi effect.
The door gap is a constricted cross-section through which the air flows very quickly.
The air pressure in the gap between the door and the frame drops.
Around the door leaf, the air usually flows at a much lower speed.
The higher pressure on the door leaf compared to the air pressure in the gap, therefore slams the door with great force, even if the air stream flows with the opening direction of the door! https://www.tec-science.com/mechanics/gases-and-liquids/examples-of-applications-of-the-bernoulli-effect/