maťa drapova gjar tmf-team 2013. fire hose consider a hose with a water jet coming from its nozzle....
TRANSCRIPT
Maťa Drapova GJAR TMF-team 2013
Fire hose
Consider a hose with a water jet coming from its nozzle. Release the hose and observe its subsequent motion. Determine the parameters that affect this motion.
Teoretically
Water jet flowing in the hose, what is happening:
1. water fill the hose completely2. the hose is under pressure3. tries to get straight
Practically
Hose type: „B“ „C“Lenght: 20m 20mWeight: 44kg + 50kg (with water) 54kg + 100kg (H2O)
Diameter: 52 mm 75mmVolume: 200l 400l
What we’ve got:
What we did:
1. we composed the hoose to folds (1-7)2. we made various spirals with differents
diameters or coils (6-22)3. we let the hose behave under differents
pressures
Then we just left it behave:
Practically• fluid mechanics theory• red pointers = arrows• force is the reason for the
change of the direction of the move(not change of move)
• equal and opposite forces
type „C“
What it looked like: Pressure: Time of filling: Other infos:
0,25 MPa 5,97sLength of fold:
5,30 m Number of folds:
1
0,25 MPa 4,45sLength of fold:
1,9mNumber of folds:
4
0,25 MPa 4,3sLength of fold:
1mNumber of folds:
7
0,25 MPa 2,3sLenght of fold:
0mNumber of folds:
0
What it looked like: Pressure: Time of filling: Diameter of the spiral: N° of coils:
4:39 – 4:49 0,25 MPa 4,1s 38 cm 22
9:05 – 9:15 0,25 MPa 3,3s 130 cm 6
16:50- 17:02 0,25 MPa 4,4s 85 cm 10
type „B“
Other: Pressure: Time of filling:
Number of folds:1
Lenght of fold:5,30m
0,25 MPa 6,8s
Number of folds:4
Lenght of fold:1,90m
0,25 MPa 6,4s
Number of folds:7
Lenght of fold:1m
0,25 MPa 4,7s
Number of folds:0
Lenght of fold:0m
0,25 MPa 3,6s
Conclusion
- graph of the dependence
of time of filling the hose and number of fold we did
- we see that the increased diameter (and volume) affected the time of filling 0 1 2 3 4 5 6 7 8
0
1
2
3
4
5
6
7
8
CB
Number of folds
Time of filling [s]
Sources:
• http://www.ehow.com/facts_6940037_fire-recoil-water-turned-on_.html
• http://physedu.science.upjs.sk/kvapaliny/rovkonti.htm
• http://www.off-ladhyx.polytechnique.fr/publications/documents/doare2002rp-2pp.pdf
• http://www.newton.dep.anl.gov/askasci/phy99/phy99x11.htm
SPECIAL THANKS TO: