PSI values on the Explosion Yield page

[Vzearr]

A lot of users tend to follow the explosion yield page when making explosion/shockwave calculations, but a common mistake I often notice is the misuse of the "20 psi" value. Many users don't know any better and use it because the page states it's the general standard. I propose we remove that and replace it with something like this. The reason for this is that many explosions in fiction don't actually have 20 psi pressure, and this can help users better understand what psi value they should use for explosions. I'm more than willing to add things, remove things, etc. This is just a rough draft of it.

Sources for this addition:​

• https://www.cdc.gov/niosh/docket/archive/pdfs/NIOSH-125/125-ExplosionsandRefugeChambers.pdf
• http://thescipub.com/pdf/10.3844/jcssp.2012.1520.1530
• https://response.restoration.noaa.gov/oil-and-chemical-spills/chemical-spills/resources/overpressure-levels-concern.html#:~:text=Overpressure, also called a blast,more damaging the pressure wave.

Note: A lot of this is from Antoniofer's blog, I just changed some stuff around and added some values.

 

[Vzearr]

Tagging random calc group members (sorry): @Mr. Bambu @SeijiSetto @Psychomaster35 @Damage3245 @CloverDragon03 @Flashlight237

 

[Mr. Bambu]

Tagging random calc group members (sorry): @Mr. Bambu @SeijiSetto @Psychomaster35 @Damage3245 @CloverDragon03 @Flashlight237

 

[Mr. Bambu]

anyways if this just proposes to add the table you have in the blog, I'm fine with that change.

 

[Flashlight237]

Yeah, I can see how that can be an issue. I've dealt with explosions with many effects. This one I recently calc'd used 1 psi based on the overpressure rating used for, keyword, "light injuries": https://vsbattles.fandom.com/wiki/U...Attorney_Feat:_Sarge_Lights_Up_the_Courthouse

At the same time, I found that apparently 25 psi is required to send people flying, which I've made use of in this calc: https://vsbattles.fandom.com/wiki/User_blog:Flashlight237/Nokotan's_Antler_Grenade

With the source being this: https://apps.dtic.mil/sti/tr/pdf/AD0067365.pdf

This one I evaluated largely involved heat with overpressure taking the backseat big time, and DontTalkDT KINDA told me to recommend thermal radiation (found in the Nuclear Secrecy blog already linked in the wiki).: https://vsbattles.fandom.com/wiki/User_blog:StrymULTRA/Undertale:_Undyne's_house_gets_a_lil'_heated

Point is, I personally wholeheartedly agree that we should remind people to look at the actual effects of the explosions rather than just assume 20 psi overpressure willy-nilly.

Btw, in case you missed any, here's the Wikipedia article on overpressure: https://en.wikipedia.org/wiki/Overpressure

This article is cited for effects on humans: https://www.cdc.gov/niosh/docket/archive/pdfs/niosh-125/125-explosionsandrefugechambers.pdf

 

[CloverDragon03]

I share the same thoughts as Bambu. In addition, here's another source that provides environmental effects for 1, 3, 5, 10, and 20 psi

 

[Flashlight237]

I share the same thoughts as Bambu. In addition, here's another source that provides environmental effects for 1, 3, 5, 10, and 20 psi

Lol, that's the same chart Wikipedia borrowed from! Not sure where the H the 2 psi figure came from tho.

 

[CloverDragon03]

Me neither, at least this way though there's a proper source on it

This source also helps with the air blast formula, as the 0.28 value used in said formula only applies to 20 PSI and they provide different values for the other mentioned PSI values

 

[Flashlight237]

Me neither, at least this way though there's a proper source on it

This source also helps with the air blast formula, as the 0.28 value used in said formula only applies to 20 PSI and they provide different values for the other mentioned PSI values

Yeah. Problem is the constants only appear on the specific overpressure values. I had to work out an approximate from NUKEMAP to get a rough value for a 25 psi blast.

 

[CloverDragon03]

I think in most cases we're probably just gonna use one of those. Not that there aren't cases where a more specific value would need to be found, but I imagine such cases would be few and far between

 

[Vzearr]

Bump.

 

[Flashlight237]

Bumpity-bump.

 

[Antvasima]

@DontTalkDT @Executor_N0 @Therefir @Ugarik @DMUA @Damage3245 @TheRustyOne @DemonGodMitchAubin @Jasonsith @Wokistan @Armorchompy @Migue79 @Psychomaster35 @Dark-Carioca @AbaddonTheDisappointment @Aguywhodoesthings @Agnaa @Dalesean027 @DemiiPowa @SeijiSetto @SunDaGamer

Are you willing to help evaluate this as well please?

 

[DMUA]

Usually I just correct people whenever something's clearly below 20 PSI, so an addition to the page pointing to those suggestions ahead of time is cool in my book

 

[Armorchompy]

I think this is a good addition

 

[Antvasima]

Thank you to everybody who are helping out here.

 

[Flashlight237]

Anyway, since the sandbox covered only the destruction effects, I'll cover the damage effects on people specifically. These are all the values I've gotten, going for the lowest ratings stated for accuracy's sake.:

1 psi: Light injuries. Bare minimum recommended for intent to harm personnel.
3 psi: Serious injuries occur. Bare minimum for fatalities.
5 psi: Universal injuries occur. Fatalities are widespread
10 psi: Most people are killed.
20 psi: Fatalities approach 100%

Since @DontTalkDT is likely to interpret the military document I previously linked differently, I'll list the last rating as such:

10.3-25 psi: People sent flying at least 3 m/s (equivalent to 45 cm vertically)

 

[Vzearr]

Anyway, since the sandbox covered only the destruction effects, I'll cover the damage effects on people specifically. These are all the values I've gotten, going for the lowest ratings stated for accuracy's sake.:

1 psi: Light injuries. Bare minimum recommended for intent to harm personnel.
3 psi: Serious injuries occur. Bare minimum for fatalities.
5 psi: Universal injuries occur. Fatalities are widespread
10 psi: Most people are killed.
20 psi: Fatalities approach 100%

Since @DontTalkDT is likely to interpret the military document I previously linked differently, I'll list the last rating as such:

10.3-25 psi: People sent flying at least 3 m/s (equivalent to 45 cm vertically)

I'll add these soon, but I'd like to include a disclaimer as well. Fiction often isn't consistent with the 10.3 psi - 25 psi threshold for sending people flying. I've seen this happen in fiction with explosions that are no more than 0.15 psi. That's why I'd prefer a disclaimer like 'please refer to destruction effects of an explosion first'.

A good example of that is this feat, characters are sent flying into the air, but the wooden building has effects I'd expect from a 6-8 psi explosion.

 

[Flashlight237]

I'll add these soon, but I'd like to include a disclaimer as well. Fiction often isn't consistent with the 10.3 psi - 25 psi threshold for sending people flying. I've seen this happen in fiction with explosions that are no more than 0.15 psi. That's why I'd prefer a disclaimer like 'please refer to destruction effects of an explosion first'.

A good example of that is this feat, characters are sent flying into the air, but the wooden building has effects I'd expect from a 6-8 psi explosion.

I personally think the effects on people and structures should be accounted for in equal weight, as certain structures or locales wouldn't have the things required to gauge destruction like windows and supports. I do, however, prefer the values I grabbed here as otherwise, we'd be getting a minimum 35 psi overpressure (I'm not joking) as the bare minimum for death, which kinda makes me cringe.

 

[Aguywhodoesthings]

I agree with the change

 

[Vzearr]

I personally think the effects on people and structures should be accounted for in equal weight, as certain structures or locales wouldn't have the things required to gauge destruction like windows and supports. I do, however, prefer the values I grabbed here as otherwise, we'd be getting a minimum 35 psi overpressure (I'm not joking) as the bare minimum for death, which kinda makes me cringe.

I added it.

 

[Dalesean027]

The additions here are fine to me

 

[TheRustyOne]

Looks good.

I'm fine with adding these PSI values to the page, though I cannot evaluate the validity of the values themselves.

 

[SunDaGamer]

I'm fine with adding PSI values too, having them all standardized and on the page makes things less of a headache for everyone involved in explosion calcs

 

[Antvasima]

It seems like we have gathered sufficient support to apply this change.

@Just_a_Random_Butler

Are you willing to handle the resulting wiki reorganisation work?

 

[Just_a_Random_Butler]

It seems like we have gathered sufficient support to apply this change.

@Just_a_Random_Butler

Are you willing to handle the resulting wiki reorganisation work?

Alright, I did it, but I don't think much reorganization was needed on my part since the changes weren't that big.

 

[Antvasima]

Thank you greatly for helping out.

Is there anything left to do here, or should we close this thread?

 

[Dalesean027]

Thank you greatly for helping out.

Is there anything left to do here, or should we close this thread?

It'w all been applied already for a while so it can be closed

 

[Antvasima]

Okay. I will do so. Thank you to everybody who helped out here.