Extraordinary EnginesBackgroundEnergy has many different forms like gravitational, kinetic, electrical, chemical energy and as we know from Albert Einstein, even mass. According to the first law of thermodynamics the total amount of energy remains constant and can only be converted from one form into another. We are familiar with processes like the acceleration of a stone falling to earth (conversion of gravitational into kinetic energy), or the burning of gasoline to drive our car (conversion of chemical into kinetic energy). But what about "water" that drives a swinging object or generating electricity from falling water drops? Can you imagine the direct conversion of light into rotational movement? Or the conversion of heat into kinetic energy in an engine mainly built of a special metal wire?Our Devices |
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Bird - Movable Device driven by Water Evaporation At first sight our Bird appears to be just a toy. But in fact it demonstrates a lot of thermodynamic phenomena: cooling by evaporation, the dependence of vapor pressure on temperature and the resulting force on a liquid column from the vapor pressure. The wet bird's head is cooled by the evaporation of the water, reducing the pressure above the blue fluid inside the bird's neck. As the pressure above the liquid column is lower than that below it, the column of liquid is forced upwards, changing the center of mass and making the whole bird swing around the axis between his legs ... Just the small temperature differential between the surrounding air and the "cooled" bird's head is sufficient to generate the mechanical movement. |
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ElectrostaticMotor - Engine converting electrostatic Energy into rotational Movement The ElectrostaticMotor provides a dynamic demonstration of electrostatic attraction and repulsion. The device consists of a spoked conductive wheel that rotates in the vertical plane on a precision ball bearing. When the two stationary conductors, mounted 180° apart, are connected to an electrostatic source (charged rod, Van de Graaff Generator, Kelvin Engine etc.), the wheel rotates due to the alternating attraction and repulsion between the spokes and the stationary conductors and thus clearly demonstrates the conversion of electrostatic into kinetic energy. |
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Heatmobile - Memory Metal Engine driven by hot Water Heatmobile - a successor of the famous Thermobile of Frederick Wang - is back on the market. The Heatmobile is a very special kind of heat engine that demonstrates the conversion of heat into mechanical energy. It uses the unique property of Nitinol alloy (~50% Nickel, ~50% Titanium, the "nol" at the end of Nitinol refers to Naval Ordnance Laboratory in Maryland USA where this alloy has been developed) called the "memory effect". Once Nitinol has been formed into shape at high temperature (about 600° C) and allowed to cool to room temperature, it can be easily deformed. However, when heated above a transition temperature (in this application about 50° C to 70° C) the Nitinol object abruptly returns to its high-temperature shape with substantially more force than that required to deform it when cold. Heatmobile uses a Nitinol wire formed to a closed loop that drives the two connected wheels. |
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KelvinEngine - Engine converting Energy of falling |
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Radiometer - Thermal Repulsion Drive The original Radiometer was invented by Sir William Crookes in the mid-nineteenth century to measure the intensity of radiant energy. The glass bulb contains an object that looks like a weather vane. Opposite sides of each metal vane are matt black and silvered. As light hits the vanes (sunlight, indoor light), the polished side reflects the light while the dark side absorbs it and this results in a temperature difference between the two sides of the vane. As the air molecules inside the bulb "kick" away from the hot dark side, they transfer momentum causing the vane to spin. Note: The rotation of the radiometer vane is not related to the momentum of the photons (the particles associated with light itself) as often stated; as Crookes found, if the bulb is (almost) completely evacuated the vanes do not turn. |
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Seesaw - Candle Bimetal Engine The bimetal spiral spring is the key component of this engine. A bimetal consists of two metals with different rates of expansion when heated. When the spiral spring is heated over the candle, it twists moving the bead to the other side making the see-saw tip over. This moves the spiral spring away from the flame, the bimetal spring cools down until it has contracted enough to make the see-saw tip back into its original position and start the cycle again. |
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KeywordsThermal Energy, Mechanical Work, Energy Conversion, Heat Engine, Memory Metal Engine, Nitinol, Wire Engine, Drinking Bird, Dippy Bird, Happy Bird, Kelvin's Engine, Kelvin Water Dropper, Kelvin's Thunderstorm, Crookes Radiometer, Light Mill, Solar Engine, Bimetal Engine, Johnson, Wang
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