Talk:3016: Cold Air - Revision history

ChaoticNeutralCzech: Prokop Diviš opinion

2024-11-27T17:43:17Z

Prokop Diviš opinion

162.158.154.35 at 15:01, 27 November 2024

2024-11-27T15:01:36Z

162.158.154.34 at 15:00, 27 November 2024

2024-11-27T15:00:01Z

141.101.98.50 at 14:05, 27 November 2024

2024-11-27T14:05:45Z

172.69.71.160: discussion on talk page

2024-11-27T09:41:47Z

discussion on talk page

RIIW - Ponder it: Wind speed to damage factor

2024-11-27T09:12:57Z

Wind speed to damage factor

172.69.194.184 at 09:11, 27 November 2024

2024-11-27T09:11:10Z

172.71.99.67: refrigeration vs. expansion cooling

2024-11-27T08:19:15Z

refrigeration vs. expansion cooling

172.69.195.200 at 00:13, 27 November 2024

2024-11-27T00:13:43Z

PRR at 23:32, 26 November 2024

2024-11-26T23:32:01Z

← Older revision		Revision as of 17:43, 27 November 2024
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	The comparison to Hiroshima is based on a compressed gas energy calculation, U = PV/(g-1) * {1 - (p/P)^[(g-1)/g]}, where P is the stored pressure, p is the outside pressure, V is the volume of the storage vessel, and g is the ratio of specific heats (1.4 for air). Took V = 75 million m^3, as estimated above.[[Special:Contributions/162.158.154.34\|162.158.154.34]] 15:00, 27 November 2024 (UTC)		The comparison to Hiroshima is based on a compressed gas energy calculation, U = PV/(g-1) * {1 - (p/P)^[(g-1)/g]}, where P is the stored pressure, p is the outside pressure, V is the volume of the storage vessel, and g is the ratio of specific heats (1.4 for air). Took V = 75 million m^3, as estimated above.[[Special:Contributions/162.158.154.34\|162.158.154.34]] 15:00, 27 November 2024 (UTC)
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		+	I like the {{w\|Prokop Diviš}} mention but was he really a ''fringe'' scientist for also being a theologist and suggesting weather control in the 1700s? Some of his ideas were functional: he invented the lightning rod around the same time and independently of Benjamin Franklin but spectacularly failed with its marketing by underestimating how superstitious his village was (they thought it was causing a drought and took it down; later in storm season some houses burned down and vilagers changed their mind but Diviš refused to reinstate it). [[User:ChaoticNeutralCzech\|ChaoticNeutralCzech]] ([[User talk:ChaoticNeutralCzech\|talk]]) 17:43, 27 November 2024 (UTC)

← Older revision		Revision as of 15:01, 27 November 2024
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	So, not a fluid dynamics expert here, but are we sure that using a naive equation for fluid flow will provide the right figure here? My understanding is that near the speed of sound, fluid flow becomes choked and limited to ~ the speed of sound. Although in the past I was mainly investigating this in the context of STP air flowing into a vacuum, so maybe the high pressure changes it. - Buggy, not a registered user {{unsigned ip\|172.69.71.160\|09:41, 27 November 2024}}		So, not a fluid dynamics expert here, but are we sure that using a naive equation for fluid flow will provide the right figure here? My understanding is that near the speed of sound, fluid flow becomes choked and limited to ~ the speed of sound. Although in the past I was mainly investigating this in the context of STP air flowing into a vacuum, so maybe the high pressure changes it. - Buggy, not a registered user {{unsigned ip\|172.69.71.160\|09:41, 27 November 2024}}

−	The comparison to Hiroshima is based on a compressed gas energy calculation, U = PV/(g-1) * (1 - (p/P)^((g-1)/g)), where P is the stored pressure, p is the outside pressure, V is the volume of the storage vessel, and g is the ratio of specific heats (1.4 for air). Took V = 75 million m^3, as estimated above.[[Special:Contributions/162.158.154.34\|162.158.154.34]] 15:00, 27 November 2024 (UTC)	+	The comparison to Hiroshima is based on a compressed gas energy calculation, U = PV/(g-1) * {1 - (p/P)^[(g-1)/g]}, where P is the stored pressure, p is the outside pressure, V is the volume of the storage vessel, and g is the ratio of specific heats (1.4 for air). Took V = 75 million m^3, as estimated above.[[Special:Contributions/162.158.154.34\|162.158.154.34]] 15:00, 27 November 2024 (UTC)

@@ Line 16: / Line 16: @@
 The statement that 3000PSI is 6x higher than known high pressure systems is false. Scuba tanks contain air at this pressure (240bar/3000psi) and the systems used to fill scuba tanks are twice that. {{unsigned ip|172.71.26.101|09:28, 26 November 2024}}
 :Perform the wiki magic and add that source!--[[User:FrankHightower|FrankHightower]] ([[User talk:FrankHightower|talk]]) 15:04, 26 November 2024 (UTC)
 [https://www.google.com/search?q=40+Bar+to+psi My calculator (Google)] says 400MPH is 644 KPH (not 500). Also 40 Bar seems to be well on the high side of 500psi (580psi).
@@ Line 36: / Line 37: @@
 So, not a fluid dynamics expert here, but are we sure that using a naive equation for fluid flow will provide the right figure here? My understanding is that near the speed of sound, fluid flow becomes choked and limited to ~ the speed of sound. Although in the past I was mainly investigating this in the context of STP air flowing into a vacuum, so maybe the high pressure changes it. - Buggy, not a registered user {{unsigned ip|172.69.71.160|09:41, 27 November 2024}}

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 :::Hmmm... "English to Metric". Strange phrase, for ''various'' reasons. ;) [[Special:Contributions/172.69.195.200|172.69.195.200]] 00:13, 27 November 2024 (UTC)
-So my brief wikihole dive has me doubting again; but is the part about requiring refrigeration accurate? By my understanding, pressurising the air in the first place would raise its temperature. It then goes back to equilibrium with the environment while it's stored at pressure, and temperature drops when it's released.
+So my brief wikihole dive has me doubting again; but is the part about requiring refrigeration accurate? By my understanding, pressurising the air in the first place would raise its temperature. It then goes back to equilibrium with the environment while it's stored at pressure, and temperature drops when it's released. {{unsigned ip|172.71.99.67|08:19, 27 November 2024}}
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-So, not a fluid dynamics expert here, but are we sure that using a naive equation for fluid flow will provide the right figure here? My understanding is that near the speed of sound, fluid flow becomes choked and limited to ~ the speed of sound. Although in the past I was mainly investigating this in the context of STP air flowing into a vacuum, so maybe the high pressure changes it. - Buggy, not a registered user
+So, not a fluid dynamics expert here, but are we sure that using a naive equation for fluid flow will provide the right figure here? My understanding is that near the speed of sound, fluid flow becomes choked and limited to ~ the speed of sound. Although in the past I was mainly investigating this in the context of STP air flowing into a vacuum, so maybe the high pressure changes it. - Buggy, not a registered user {{unsigned ip|172.69.71.160|09:41, 27 November 2024}}

← Older revision		Revision as of 09:41, 27 November 2024
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	Just heard on the BBC Science in Action podcast 21November - the USA research group Climate Action, has shown that the damage due to wind goes up with the eighth power of the speed. Thus 9% increase results in twice the damage! Would help to explain some of the magnitude of the peaks on the graph! [[User:RIIW - Ponder it\|RIIW - Ponder it]] ([[User talk:RIIW - Ponder it\|talk]]) 09:12, 27 November 2024 (UTC)		Just heard on the BBC Science in Action podcast 21November - the USA research group Climate Action, has shown that the damage due to wind goes up with the eighth power of the speed. Thus 9% increase results in twice the damage! Would help to explain some of the magnitude of the peaks on the graph! [[User:RIIW - Ponder it\|RIIW - Ponder it]] ([[User talk:RIIW - Ponder it\|talk]]) 09:12, 27 November 2024 (UTC)
		+
		+
		+	So, not a fluid dynamics expert here, but are we sure that using a naive equation for fluid flow will provide the right figure here? My understanding is that near the speed of sound, fluid flow becomes choked and limited to ~ the speed of sound. Although in the past I was mainly investigating this in the context of STP air flowing into a vacuum, so maybe the high pressure changes it. - Buggy, not a registered user

← Older revision		Revision as of 09:12, 27 November 2024
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	So my brief wikihole dive has me doubting again; but is the part about requiring refrigeration accurate? By my understanding, pressurising the air in the first place would raise its temperature. It then goes back to equilibrium with the environment while it's stored at pressure, and temperature drops when it's released.		So my brief wikihole dive has me doubting again; but is the part about requiring refrigeration accurate? By my understanding, pressurising the air in the first place would raise its temperature. It then goes back to equilibrium with the environment while it's stored at pressure, and temperature drops when it's released.
		+
		+
		+	Just heard on the BBC Science in Action podcast 21November - the USA research group Climate Action, has shown that the damage due to wind goes up with the eighth power of the speed. Thus 9% increase results in twice the damage! Would help to explain some of the magnitude of the peaks on the graph! [[User:RIIW - Ponder it\|RIIW - Ponder it]] ([[User talk:RIIW - Ponder it\|talk]]) 09:12, 27 November 2024 (UTC)

@@ Line 24: / Line 24: @@
 :The source says tornadoes go up to 318 mph (512 kph) but the [https://en.wikipedia.org/wiki/1999_Bridge_Creek%E2%80%93Moore_tornado strongest tornado on record] exceeded that. I couldn't confirm when I wrote whether that was ''actually'' the strongest, and since the only purpose of the number is to say "Cueball's windspeeds are way, way worse", I decided an upper bound of 400 covered it.--[[User:FrankHightower|FrankHightower]] ([[User talk:FrankHightower|talk]]) 15:04, 26 November 2024 (UTC)
-"I decided an upper bound of 400 covered it." Somebody edited my words and omitted the key point: ARITHMETIC. English to Metric is NOT 4:5. --[[User:PRR|PRR]] ([[User talk:PRR|talk]]) 23:32, 26 November 2024 (UTC)
+::"I decided an upper bound of 400 covered it." Somebody edited my words and omitted the key point: ARITHMETIC. English to Metric is NOT 4:5. --[[User:PRR|PRR]] ([[User talk:PRR|talk]]) 23:32, 26 November 2024 (UTC)
-:Hmmm... "English to Metric". Strange phrase, for ''various'' reasons. ;) [[Special:Contributions/172.69.195.200|172.69.195.200]] 00:13, 27 November 2024 (UTC)
+:::Hmmm... "English to Metric". Strange phrase, for ''various'' reasons. ;) [[Special:Contributions/172.69.195.200|172.69.195.200]] 00:13, 27 November 2024 (UTC)
 So my brief wikihole dive has me doubting again; but is the part about requiring refrigeration accurate? By my understanding, pressurising the air in the first place would raise its temperature. It then goes back to equilibrium with the environment while it's stored at pressure, and temperature drops when it's released.

← Older revision		Revision as of 08:19, 27 November 2024
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	"I decided an upper bound of 400 covered it." Somebody edited my words and omitted the key point: ARITHMETIC. English to Metric is NOT 4:5. --[[User:PRR\|PRR]] ([[User talk:PRR\|talk]]) 23:32, 26 November 2024 (UTC)		"I decided an upper bound of 400 covered it." Somebody edited my words and omitted the key point: ARITHMETIC. English to Metric is NOT 4:5. --[[User:PRR\|PRR]] ([[User talk:PRR\|talk]]) 23:32, 26 November 2024 (UTC)
	:Hmmm... "English to Metric". Strange phrase, for ''various'' reasons. ;) [[Special:Contributions/172.69.195.200\|172.69.195.200]] 00:13, 27 November 2024 (UTC)		:Hmmm... "English to Metric". Strange phrase, for ''various'' reasons. ;) [[Special:Contributions/172.69.195.200\|172.69.195.200]] 00:13, 27 November 2024 (UTC)
		+
		+	So my brief wikihole dive has me doubting again; but is the part about requiring refrigeration accurate? By my understanding, pressurising the air in the first place would raise its temperature. It then goes back to equilibrium with the environment while it's stored at pressure, and temperature drops when it's released.

← Older revision		Revision as of 00:13, 27 November 2024
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	"I decided an upper bound of 400 covered it." Somebody edited my words and omitted the key point: ARITHMETIC. English to Metric is NOT 4:5. --[[User:PRR\|PRR]] ([[User talk:PRR\|talk]]) 23:32, 26 November 2024 (UTC)		"I decided an upper bound of 400 covered it." Somebody edited my words and omitted the key point: ARITHMETIC. English to Metric is NOT 4:5. --[[User:PRR\|PRR]] ([[User talk:PRR\|talk]]) 23:32, 26 November 2024 (UTC)
		+	:Hmmm... "English to Metric". Strange phrase, for ''various'' reasons. ;) [[Special:Contributions/172.69.195.200\|172.69.195.200]] 00:13, 27 November 2024 (UTC)

← Older revision		Revision as of 23:32, 26 November 2024
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	:The source says tornadoes go up to 318 mph (512 kph) but the [https://en.wikipedia.org/wiki/1999_Bridge_Creek%E2%80%93Moore_tornado strongest tornado on record] exceeded that. I couldn't confirm when I wrote whether that was ''actually'' the strongest, and since the only purpose of the number is to say "Cueball's windspeeds are way, way worse", I decided an upper bound of 400 covered it.--[[User:FrankHightower\|FrankHightower]] ([[User talk:FrankHightower\|talk]]) 15:04, 26 November 2024 (UTC)		:The source says tornadoes go up to 318 mph (512 kph) but the [https://en.wikipedia.org/wiki/1999_Bridge_Creek%E2%80%93Moore_tornado strongest tornado on record] exceeded that. I couldn't confirm when I wrote whether that was ''actually'' the strongest, and since the only purpose of the number is to say "Cueball's windspeeds are way, way worse", I decided an upper bound of 400 covered it.--[[User:FrankHightower\|FrankHightower]] ([[User talk:FrankHightower\|talk]]) 15:04, 26 November 2024 (UTC)

−	"I decided an upper bound of 400 covered it." Somebody edited my words and omitted the key point: ARITHMETIC. English to Metric is NOT 4:5.	+	"I decided an upper bound of 400 covered it." Somebody edited my words and omitted the key point: ARITHMETIC. English to Metric is NOT 4:5. --[[User:PRR\|PRR]] ([[User talk:PRR\|talk]]) 23:32, 26 November 2024 (UTC)