How much force from Atmospheric Pressure Change

[Peterae]

OK so i'm looking up the UK weather map and checked the pressures, i can see a high of 1032mb and a low of 972mb on the map, although these are not directly over the UK but just want to get an idea of the max and min on the chart.

So we have a change in pressure between 1032mb & 972mb giving us a pressure change of 60mb

So then i went to a conversion site to convert mbar into something i recognize as metric ie kgf/m2 and put in 60mb

The answer is staggering 611.83 kg per meter squared, obviously something must be wrong otherwise we would have an incredible energy source right under our noses.

So what went wrong?

[evolvingape]

Atmospheric pressure is gas pressure and 60 millibars = 611.8 kgf/m2, Kilograms Force per square Meter. 1Kg = 2.2 lbs (Pounds)

http://www.convert-me.com/en/convert/pressure/millibar.html

I work in psi (Pounds per square Inch) and 60 mb = 0.87 psi

https://en.wikipedia.org/wiki/Contour_line#Barometric_pressure

An isobar (from βάρος or baros, meaning 'weight') is a line of equal or constant pressure on a graph, plot, or map; an isopleth or contour line of pressure. More accurately, isobars are lines drawn on a map joining places of equal average atmospheric pressure reduced to sea level for a specified period of time. In meteorology, the barometric pressures shown are reduced to sea level, not the surface pressures at the map locations.[9] The distribution of isobars is closely related to the magnitude and direction of the wind field, and can be used to predict future weather patterns. Isobars are commonly used in television weather reporting.

isobars are lines joining points of equal pressure change during a specific time interval.

You do have a pressure differential but it is not particularly large and it is spread out over a large area, it would not be practical to harvest this energy.

I have shown that the boundary plane between the gas and liquid layers of the Earths specific gravity field has an elastic quality tending toward equilibrium, and is at a natural over pressure of 15 psi, either side of the boundary plane (0).

Significant oscillatory rates can be achieved by creating a displacement and allowing gravitational energy forces to return the system to equilibrium.

[CITFTA]

It might be interesting to some to know that barometric pressure has been used as an energy source for close to 100 years if I recall correctly.  I remember back in the 1970's seeing a clock that was powered by the changes in barometric pressure.  A diaphragm was connected to a mechanism to wind a spring.  According to the owner of the one I saw it had been running for almost 30 years with only a cleaning and relubricating every 10 years or so.  You can probably search for barometric clock and find some info on it.  If I find a link I will share it.

Here is a link.  It is called the Atmos clock.  It actually uses changes in temperature and air pressure to power it.

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

[Grumage]

Dear Peterae and all.

I'm sure I found links to a Tesla idea of large ( power station cooling tower ) looking chimneys with a turbine within many moons ago. Has anyone else come across this?

Just think of the pressure differential of say 300 Ft !! Our own house chimney has quite a pull, thank goodness the multi fuel fire has a door fitted......Brrrrrrrrr.   

Cheers Grum.

[CITFTA]

Here is an article about using solar chimneys to power turbines for electrical production.  I don't think this is exactly what you were referring to but it does seem close to that idea.  I wonder how small they could be and still be effective.

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

Regards,
Carroll

[Paul-R]

I've always thought that there is a project in an old disused gasometer, either filling when the pressure is high and releasing through turbines when low - or alternatively, using hot and cold conditions instead.

[evolvingape]

Interesting discussion!

Pressure with Height:

http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/prs/hght.rxml

and a nice presentation on the Atmosphere of Earth:

http://www.davis.k12.ut.us/cms/lib09/UT01001306/Centricity/Domain/8080/Atmosphere.pdf

Temperature, Pressure and Density of the fluid must always be analysed for the system under observation, as well as rate of change amongst other variables.

[Grumage]

Dear All.

Few people have heard of John Ericsson but he managed to get financing to build the first Caloric engine ship. The pistons were 14 feet in diameter just imagine the atmospheric pressure on that!!

For those that might like to get a better idea, try this link. http://quod.lib.umich.edu/m/moa/AJS2743.0001.001?view=toc

Attached is my half scale Robinson hot air engine that will, on a good day, run on a nightlight candle.

Cheers Grum.

[Peterae]

Hi
Thanks for the suggestions, very interesting Grum about the Ericsson's caloric engine.
An interesting subject.

So it should be possible to build quiet an efficient engine using the solar heating tubes as the source of heat as i understand it these are very efficient heat collectors.


http://endless-solar.com.au/evacuated-tube-efficiency/


http://www.douglas-self.com/MUSEUM/POWER/hotair/hotair.htm

[evolvingape]

Few people have heard of John Ericsson but he managed to get financing to build the first Caloric engine ship. The pistons were 14 feet in diameter just imagine the atmospheric pressure on that!!

The atmospheric pressure would be one atmosphere at sea level at all points of the piston face,(1 atmosphere, 1 bar, 15psi, etc).

The pistons diameter is known but it's weight is not (gonna be heavy at 7 feet radius!).

We need more information to calculate forces involved 

http://www.engineeringtoolbox.com/pneumatic-cylinder-force-d_1273.html

http://www.engineeringtoolbox.com/hydraulic-force-calculator-d_1369.html

[Peterae]

You know this could also be applicable to wind turbines ie large surface area.

The maximum theoretical efficiency of a wind turbine if i remember has a top limit of 64% but is more like 45% due to the needed energy to exit the blades at speed, where as a flat piston would have 100% of the wind force acting on it, if a large flat plate has the full force of the wind acting on it then this could drive a crank shaft.

The energy generated is V^3 for wind speed and Area ^ 2 for the piston again i am using my memory to pull these out and clarification would be needed, so double the piston area and quadruple the force obtained.

[evolvingape]

A wind turbine like any other generator or motor is COP<1.

INPUT -> COP<1 SYSTEM OUTPUT

A fundamental force coupled system loops the COP<1 total system output back into the process as an input which manifests with a multiplier at the now COP>1 total system output.

                    ...COP>1 SYSTEM OUTPUT
                   !
INPUT -> OUTPUT -> INPUT... 
          !.............................!

The electrical medium is necessary to achieve conversion between different system energy units and is utilised solely as a bridge force in the system architecture.

[Peterae]

So at 20mph for every 1 square meter of flat vertical surface has 7.83 kg acting on it.

at 40mph we have 31.30kg/m^2

so 20mph and 9m2 then we have 70.47kg
and at 40mph and 9m2 we have 281.7kg

http://www.sussex.ac.uk/weatherstation/technical/Windforce.html

[evolvingape]

A reciprocal piston must be returned, which requires shutting off the input force temporarily.

The turbine rotates the next working face into position requiring no immediate return.

In general pistons require static head and rotors require dynamic head.