Reason of hot water 'float' on the cold water

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SUMMARY

The discussion centers on the phenomenon of hot water 'floating' on cold water, challenging the conventional understanding of density differences. The user created a model using ActionScript in Flash to simulate the behavior of hot and cold water particles, concluding that hot water remains at the top due to its energy rather than density. The conversation also highlights the need for incorporating surface tension and molecular bonding effects into the model for a more accurate representation of water behavior at different temperatures.

PREREQUISITES
  • Understanding of thermodynamics and heat transfer principles
  • Familiarity with ActionScript and Flash for simulation development
  • Basic knowledge of molecular interactions, particularly hydrogen bonding in water
  • Concept of surface tension and its effects on fluid dynamics
NEXT STEPS
  • Research the principles of fluid dynamics and how temperature affects density
  • Learn about molecular dynamics simulations and how to model interactions in fluids
  • Explore the effects of surface tension in liquids and its role in fluid behavior
  • Investigate the phenomenon of convection currents in fluids and their implications in thermal dynamics
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Students and professionals in physics, fluid dynamics researchers, software developers interested in simulation modeling, and educators seeking to explain thermal behavior in fluids.

ArielGenesis
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i think that the reason of hot water 'float' on the cold water is not because of diffrent density. i make a model of a container containing a higher energy particle (hot water) and lower energy particle (cold water) using action script in flash and uploaded it in geocities. www.geocities.com/arian_m3/heat.swf

from that, it shows that the hot water is MORE (not placed) at the top because it got the power to. while the cold water STAYS (not sink) at the bottom. And thus RESULTING (not beacuse of) a diffrent density. this might not be a perfect model of hot and cold water, but i couldn't find any better yet. the main concept of the script is to move the particle randomly and pulled it downward with gravity.

here is the code if anyone getting interested.

for the hotter particle:
onClipEvent (load) {
_x = 150;
_y = 300;
var vx = random(30)-random(30);
var vy = random(30)-random(30);
var i = 60;
if (_name == "red") {
while (i<>90) {
duplicateMovieClip(_root.red, "red"+i, i);
_parent["red"+i]._x = _x+random(50)-random(50);
_parent["red"+i]._y = _y+random(50)-random(50);
i++;
}
}
}
onClipEvent (enterFrame) {
vx += random(8)-random(8);
vy += random(8)-random(8)+1;
if (_x+vx<=10 or _x+vx>=400) {
vx *= -0.5;
}
if ( _y+vy>=590) {
vy *= -0.5;
}
_x += vx;
_y += vy;
}

and this one is for the colder particle
onClipEvent (load) {
_x = 200;
_y = 300;
var vx = random(10)-random(10);
var vy = random(10)-random(10);
var i = 0;
if (_name == "blue") {
while (i<>50) {
duplicateMovieClip(_root.blue, "blue"+i, i);
_parent["blue"+i]._x = _x+random(50)-random(50);
_parent["blue"+i]._y = _y+random(50)-random(50);
i++;
}
}
}
onClipEvent (enterFrame) {
vx += random(5)-random(5);
vy += random(5)-random(5)+1;
if (_x+vx<=10 or _x+vx>=400) {
vx *= -0.5;
}
if ( _y+vy>=590) {
vy *= -0.5;
}
_x += vx;
_y += vy;
}

feel free to fix my error.
 
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ArielGenesis said:
feel free to fix my error.

Then explain why water at 0C "floats" on top of water at 4C. According to your "model", water at 4C should have "more power" and should be on top of water at 0C. This is certainly not the case since water at 1C or 0C that eventually solidify into ice is on top.

Zz.
 
Neat flik! Looks like a gas though, and I don't see anything in your program regarding surface tension. The flash you have seems to simulate a gas in a gravitational field fairly well. Add the surface tension affects and bonding affects between molecules, then some pressure above the surface, and you may see some differences in the model.
 
Since the code is not self-explanatory, it seems that (from the brief intro in the OP) your hamiltonian contains a kinetic term and a potential term (gravitational) but no interaction terms arising from hydrogen bonding.
 
Q_Goest said:
Neat flik! Looks like a gas though, and I don't see anything in your program regarding surface tension. The flash you have seems to simulate a gas in a gravitational field fairly well. Add the surface tension affects and bonding affects between molecules, then some pressure above the surface, and you may see some differences in the model.
My first reaction too...water isn't a gas. Cool animation though.
 
okay, i think it is my fault, it is gas then, my friend also told me that.

so... what I'm thinking is that if i could make a model of heatting (i failed to make it), following the logic, there could be no convection current
 

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