Fuel

[benparry]

Good Morning

can i ask a question which i'm sure has an easy answer.

the first stage of Apollo launch with the F1 Rockets used 318000 gallons of LOX and 203400 gallons of Kerosene.

i have read that the mixture ratio needed was 2.27 to 1 LOX to Fuel.

shouldnt there be more LOX in there as 2.27 times 203400 is 461718 not 318000

again i'm sure i've missed something.

is there an easy answer

cheers

Ben

[Zakalwe]

Was the ratio based on mass or volume?

[benparry]

Was the ratio based on mass or volume?

it was just from a chart I saw on a site. let me get it for you.

https://www.space.com/18422-apollo-saturn-v-moon-rocket-nasa-infographic.html

if you see the black rectangle directly under the picture of the rocket it says 2.27 to 1 in there

cheers Zakalwe

[bknight]

I don't see the graph you referred, but from the AS-506 Post flight report

https://ia600307.us.archive.org/32/items/nasa_techdoc_19900066485/19900066485.pdf

page 5-6

1500418 kg LOX; 646854 kg Kerosene at ignition
           18177 kg LOX; 14354 kg Kerosene at OECO 

Thus from ignition to Outside Engine Cut Off 1482241 kg LOX burned 632500 kg Kerosene burned for an AVERAGE Ratio of  2.34.
 

[benparry]

I don't see the graph you referred, but from the AS-506 Post flight report

https://ia600307.us.archive.org/32/items/nasa_techdoc_19900066485/19900066485.pdf

page 5-6

1500418 kg LOX; 646854 kg Kerosene at ignition
           18177 kg LOX; 14354 kg Kerosene at OECO 

Thus from ignition to Outside Engine Cut Off 1482241 kg LOX burned 632500 kg Kerosene burned for an AVERAGE Ratio of  2.34.
 

Hey bknight

if you open the link copied its about half way down in a black rectangle.

however are you saying that all of the fuel within the first stage wasn't used.

[Peter B]

Benparry

Note the difference. Your comparison was in gallons (volume).

Bknight's comparison was in kilograms (mass).

You might like to check the densities of liquid oxygen and kerosene.

[benparry]

Benparry

Note the difference. Your comparison was in gallons (volume).

Bknight's comparison was in kilograms (mass).

You might like to check the densities of liquid oxygen and kerosene.

Hi Peter b

Sorry I am confused. If I go back to my original post if you devide the higher figure by the lower figure you don't get 2.27. However when you look at my attachment is said that a ratio of 2.27 was used. I know I am confused can you explain where I am going wrong.

[benparry]

so if the first stage of Apollo launch with the F1 Rockets used 318000 gallons of LOX and 203400 gallons of Kerosene.

i have read that the mixture ratio needed was 2.27 to 1 LOX to Fuel.

shouldnt there be more LOX in there as 2.27 times 203400 is 461718 not 318000


again i'm sure i'm being silly here. can I also just ask was the whole of the fuel which was present in the first stage actually used or is it simply a case of you don't need to times it by 2.27 as not all of the fuel was used.


do I need to multiply the amount of LOX and fuel burned per second or minute by the number of minutes the burn took place for.

[bknight]

I don't see the graph you referred, but from the AS-506 Post flight report

https://ia600307.us.archive.org/32/items/nasa_techdoc_19900066485/19900066485.pdf

page 5-6

1500418 kg LOX; 646854 kg Kerosene at ignition
           18177 kg LOX; 14354 kg Kerosene at OECO 

Thus from ignition to Outside Engine Cut Off 1482241 kg LOX burned 632500 kg Kerosene burned for an AVERAGE Ratio of  2.34.
 

Hey bknight

if you open the link copied its about half way down in a black rectangle.

however are you saying that all of the fuel within the first stage wasn't used.

That is correct both fuel and oxidizer were left in all the stages after engine cutoff.

[bknight]

You are referencing volume as Peter indicated.  Mass is the appropriate property to use.  Look at the rocket equation:

https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation

Only MASS is used in the equation, therefore your comparison should be mass, not volume

[benparry]

You are referencing volume as Peter indicated.  Mass is the appropriate property to use.  Look at the rocket equation:

https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation

Only MASS is used in the equation, therefore your comparison should be mass, not volume

you may have guessed by my lack of knowledge but that is totally over my head.

do you know how much of both the LOX and rocket fuel were burnt per second / minute and how many second / minutes the burn lasted.

if I can multiply them in my head I can get why the LOX or fuel shouldn't have run out lol

thanks again

[benparry]

You are referencing volume as Peter indicated.  Mass is the appropriate property to use.  Look at the rocket equation:

https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation

Only MASS is used in the equation, therefore your comparison should be mass, not volume

again excuse my denseness.

if the burn lasted 2 minutes which I read then that's 120 seconds. I read that the first stage used 20000 kg per second so that's 2400000.

but above it was said that at ignition it only had 646000 kg's

again am I wrong.

[Kiwi]

Whenever you want numbers about Apollo missions, your first port of call should probably be the "Apollo by the Numbers" web pages.
https://history.nasa.gov/SP-4029/Apollo_00_Welcome.htm

This old 2007 thread at a previous version of ApolloHoax provides links for every individual web page:
https://apollohoax.proboards.com/thread/1356/apollo-numbers

Read the comments because the Nasa pages have some links that don't work, or gaps where there should be links -- hence the thread.

In the first post, page down past the individual missions to the section, "Apollo - General Information" where you'll find three pages, 18-23a to 18-23c titled  "Launch Vehicle Propellant Usage".

https://history.nasa.gov/SP-4029/Apollo_18-23a_Launch_Vehicle_Propellant_Use.htm
https://history.nasa.gov/SP-4029/Apollo_18-23b_Launch_Vehicle_Propellant_Use.htm
https://history.nasa.gov/SP-4029/Apollo_18-23c_Launch_Vehicle_Propellant_Use.htm

The fuel quantities there are in pounds, which might confirm what Peter B and bknight said about needing to work with mass (lbs or kg), not volume (gallons or litres).

PS This thread should probably be in the Reality of Apollo section, unless you're going to propose that the figures are hoaxed.

[benparry]

No I am a believer I have noticed a thread in a hoax group on facebook and I confused by the figures.

[jfb]

Good Morning

can i ask a question which i'm sure has an easy answer.

the first stage of Apollo launch with the F1 Rockets used 318000 gallons of LOX and 203400 gallons of Kerosene.

i have read that the mixture ratio needed was 2.27 to 1 LOX to Fuel.

shouldnt there be more LOX in there as 2.27 times 203400 is 461718 not 318000

again i'm sure i've missed something.

is there an easy answer

cheers

Ben

You're confusing units of measure - the mixture ratio is expressed in terms of mass (2.27 pounds LOX to 1 pound RP-1).  "Gallon" is not a unit of mass, it's a unit of volume.  LOX is denser than RP-1, so a gallon of LOX weighs more than a gallon of RP-1.  IOW, you need fewer gallons to store X pounds of LOX than to store X pounds of RP-1.   

This is why the tank volume ratio doesn't match the mass ratio.