Recent content by jon c

Please will someone consider this with me When a simple water heater burns (a propane/air mixture, for example) is energy lost when the resulting gases expand into the atmosphere? Up the exhaust flue of a domestic boiler for example. Is this how steam turbine powered ships lose out...

Nice article thankyou. I find this subject fascinating. The relationship between the large scale mechanical world and the physics of matter. Also it is amazing how these fundamental relationships (heat and force) were only fully accepted and unified about 150 years ago.

Friction without wear, does it exist? This would be mechanical heat generation without wear. If so what is the mechanism by which it works? Does anyone know of any new purely mechanical vehicle brake designs which claim zero wear for example. Nothing electrical please.

That was all good, thankyou My next question is: can there exist friction without wear? I will run this a separate thread. (This would then by definition be heat generation with no wear.) Interesting someone said that studies have been done with viscous fluids.

heat production from low wear friction - efficiency What are some efficient methods of producing heat from low wear friction? Regards

Please can someone explain the theoretical mechanisms for how heat is created from friction in low wear situations in non technical but fully reasonable terms for explanation to bright 10 years olds? Many thanks in advance. Is the only theory simply that the large scale physical motion of a...

I understand the combustion theory, and can explain it. There are animations and even some high speed films clips of internal combustion engine combustion which show this burning process very clearly. I need to find some emissions figures for boilers and efficient running car engines to compare...

So an internal combustion engine needs to run at a constant rpm, load and also be running 'lean' to have emissions comparable to domestic boilers. Many thanks. Clearly there are nitrogen and sulphur oxides created in domestic boiler hydrocarbon combustion but at lower levels than in vehicle...

Thank you Boilers run leaner (more o2) OK. I will look for some figures for LPG boiler emissions. Some of them are doing projects on CHP units. Anyone else please add your thoughts. Regards

Thank you for the reply They all know the chemistry of the combustion processes involved (including stoichiometry). They also appreciate that perfect complete combustion is not possible. Their question specifically concerns emissions from a LPG car exhaust systems compared to those from...

Hello Maybe this is a question more for chemists but then maybe not... We are talking about burnt emissions pollution in class. Comparing internal combustion engine emissions with household water heating systems (boilers) emissions. Please can anyone tell us if petrol/gasoline internal...

Hi My son (and now me too) want to know how friction develops heat. The only explanation I can think of (and that makes sense to me) is that during the rubbing molecular bonds are broken completely, or then remade at lower force levels, then the surplus energy is then transferred into heat...