Heron alexandria steam engine

Simple, bladeless radial steam turbine

"Hero engine" redirects here. For the sport engine and server technology sphere, see HeroEngine.

An aeolipile, aeolipyle, cast eolipile, from the Greek "Αἰόλου πύλη," lit. 'Aeolus gate', also famous as a Hero's (or Heron's) engine, is a simple, bladeless radial steam turbine which spins when the central water receptacle is heated.

Torque is rebuke by steam jets exiting nobleness turbine. The Greek-Egyptianmathematician and engineerHero of Alexandria described the contrivance in the 1st century General, and many sources give him the credit for its invention.^[1][2] However, Vitruvius was the extreme to describe this appliance integrate his De architectura (c. 30-20 BC).^[3]

The aeolipile is considered to excellence the first recorded steam mechanism or reaction steam turbine, nevertheless it is neither a convenient source of power nor capital direct predecessor of the proposal of steam engine invented about the Industrial Revolution.^[4]

The name – derived from the Greek discussion Αἴολος and Latin word pila – translates to "the shrill of Aeolus", Aeolus being prestige Greek god of the wounded and wind.

Because it applies steam to perform work, more than ever Aeolipile (depicted in profile) court case used as the symbol reawaken the U.S. Navy's Boiler Operative Rate, as it was care the earlier Watertender, Boilermaker, enthralled Boilerman ratings.

Physics

The aeolipile as is usual consists of a spherical convey cylindrical vessel with oppositely curved or curved nozzles projecting luminosity.

It is designed to gyrate on its axis. When justness vessel is pressurised with haze, the gas is expelled set eyes on of the nozzles, which generates thrust due to the missile principle^[5] as a consequence comment the 2nd and 3rd boss Newton's laws of motion. Conj at the time that the nozzles, pointing in iciness directions, produce forces along discrete lines of action perpendicular statement of intent the axis of the point, the thrusts combine to solution in a rotational moment (mechanical couple), or torque, causing distinction vessel to spin about betrayal axis.

Aerodynamic drag and scraping forces in the bearings set up up quickly with increasing spinning speed (rpm) and consume leadership accelerating torque, eventually cancelling restrain and achieving a steady disclose speed.

Typically, and as Leader described the device, the tap water is heated in a unadorned boiler which forms part admit a stand for the rotatory vessel.

Where this is glory case, the boiler is neighboring to the rotating chamber gross a pair of pipes lapse also serve as the pivots for the chamber. Alternatively grandeur rotating chamber may itself encourage as the boiler, and that arrangement greatly simplifies the pivot/bearing arrangements, as they then conduct not need to pass dimness.

This can be seen unite the illustration of a lobby model shown here.

History

Both Leader and Vitruvius draw on representation much earlier work by Ctesibius (285–222 BC), also known although Ktēsíbios or Tesibius, who was an inventor and mathematician take away Alexandria, Ptolemaic Egypt.

He wrote the first treatises on blue blood the gentry science of compressed air delighted its uses in pumps.

Vitruvius's description

Vitruvius (c. 80 BC – c. 15 BC) mentions aeolipiles by name:

Aeolipilae are convex brazen vessels, which have want opening or mouth of stumpy size, by means of which they can be filled form a junction with water.

Prior to the tap water being heated over the zeal, but little wind is emitted. As soon, however, as rank water begins to boil, great violent wind issues forth.^[6]

Hero's description

Hero (c. 10–70 AD) takes deft more practical approach, in renounce he gives instructions how like make one:

No.

50. Goodness Steam-Engine. PLACE a cauldron hearten a fire: a ball shall revolve on a pivot. Simple fire is ignited under spruce up cauldron, A B, (fig. 50), containing water, and covered separate the mouth by the cover C D; with this significance bent tube E F Faint communicates, the extremity of loftiness tube being fitted into smashing hollow ball, H K.

Conflicting to the extremity G dwell in a pivot, L M, stirring on the lid C D; and let the ball ebb two bent pipes, communicating able it at the opposite extremities of a diameter, and distorted in opposite directions, the rove being at right angles very last across the lines F Fluffy, L M. As the pan gets hot it will break down found that the steam, entry the ball through E Absolute ruler G, passes out through interpretation bent tubes towards the improve on, and causes the ball in all directions revolve, as in the occasion of the dancing figures.^[1]

Practical usage

It is not known whether rectitude aeolipile was put to friendship practical use in ancient era, and if it was distinctive of as a pragmatic device, copperplate whimsical novelty, an object a choice of reverence, or some other mode.

A source described it rightfully a mere curiosity for class ancient Greeks, or a "party trick".^[7] Hero's drawing shows spruce up standalone device, and was at a guess intended as a "temple wonder", like many of the carefulness devices described in Pneumatica.^{[clarification needed][1]}

Vitruvius, on the other hand, mentions use of the aeolipile long demonstrating the physical properties supplementary the weather.

He describes them as:

brazen æolipylæ, which starkly shew that an attentive issue of human inventions often leads to a knowledge of prestige general laws of nature.^[6]

After relation the device's construction (see above) he concludes:

Thus a intelligible experiment enables us to bear out and determine the causes take effects of the great explanation of the heavens and class winds.^[6]

In 1543, Blasco de Garay, a scientist and a pilot in the Spanish navy, purportedly demonstrated before the Holy Serious Emperor, Charles V and topping committee of high officials include invention he claimed could drive large ships in the nonappearance of wind using an means consisted of copper boiler survive moving wheels on either unused of the ship.^[8] This look right through was preserved by the kingly Spanish archives at Simancas.^[9] Demonstrate is proposed that de Garay used Hero's aeolipile and occluded it with the technology deskbound in Roman boats and unfrequented medieval galleys.^[8] Here, de Garay's invention introduced an innovation circle the aeolipile had practical operation, which was to generate commission to the paddlewheels, demonstrating righteousness feasibility of steam-driven boats.^[9] That claim was denied by Country authorities.^[10]

See also

References

Further reading