Ad
related to: time based efficiency formula
Search results
Results From The WOW.Com Content Network
The above efficiency formulas are based on simple idealized mathematical models of engines, with no friction and working fluids that obey simple thermodynamic rules called the ideal gas law. Real engines have many departures from ideal behavior that waste energy, reducing actual efficiencies below the theoretical values given above.
The maximum efficiency (i.e., the Carnot heat engine efficiency) of a heat engine operating between hot and cold reservoirs, denoted as H and C respectively, is the ratio of the temperature difference between the reservoirs to the hot reservoir temperature, expressed in the equation
Efficiency declines steadily with reduced power output and is very poor in the low power range. General Motors at one time manufactured a bus powered by a gas turbine, but due to rise of crude oil prices in the 1970s this concept was abandoned. Rover, Chrysler, and Toyota also built prototypes of turbine-powered cars. Chrysler built a short ...
A Carnot cycle is an ideal thermodynamic cycle proposed by French physicist Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. By Carnot's theorem, it provides an upper limit on the efficiency of any classical thermodynamic engine during the conversion of heat into work, or conversely, the efficiency of a refrigeration system in creating a temperature difference through ...
The importance of efficiency with respect to time was emphasized by Ada Lovelace in 1843 as applied to Charles Babbage's mechanical analytical engine: "In almost every computation a great variety of arrangements for the succession of the processes is possible, and various considerations must influence the selections amongst them for the purposes of a calculating engine.
Unlike efficacy (effectiveness), which is a unit of measurement, efficiency is a unitless number expressed as a percentage, requiring only that the input and output units be of the same type. The luminous efficiency of a light source is thus the percentage of luminous efficacy per theoretical maximum efficacy at a specific wavelength.
Carnot engine diagram (modern) - where an amount of heat Q H flows from a high temperature T H furnace through the fluid of the "working body" (working substance) and the remaining heat Q C flows into the cold sink T C, thus forcing the working substance to do mechanical work W on the surroundings, via cycles of contractions and expansions.
The Nash–Sutcliffe coefficient masks important behaviors that if re-cast can aid in the interpretation of the different sources of model behavior in terms of bias, random, and other components. [11]