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Mathematically, it is represented as =, [1] where is the cycle efficiency and is the propulsive efficiency. The cycle efficiency is expressed as the percentage of the heat energy in the fuel that is converted to mechanical energy in the engine, and the propulsive efficiency is expressed as the proportion of the mechanical energy actually used ...
Most air conditioners have a COP of 2.3 to 3.5. [4] When talking about the efficiency of heat engines and power stations the convention should be stated, i.e., HHV (a.k.a. Gross Heating Value, etc.) or LCV (a.k.a. Net Heating value), and whether gross output (at the generator terminals) or net output (at the power station fence) are being ...
The efficiency of internal combustion engines depends on several factors, the most important of which is the expansion ratio. For any heat engine the work which can be extracted from it is proportional to the difference between the starting pressure and the ending pressure during the expansion phase.
The efficiency of the Diesel cycle is dependent on r and γ like the Otto cycle, and also by the cutoff ratio, r c, which is the ratio of the cylinder volume at the beginning and end of the combustion process: [4] = () The Diesel cycle is less efficient than the Otto cycle when using the same compression ratio.
As can be seen in the formula for maximum theoretical thermal efficiency in an ideal Brayton cycle engine, a high pressure ratio leads to higher thermal efficiency: = where PR is the pressure ratio and gamma the heat capacity ratio of the fluid, 1.4 for air.
Volumetric efficiency (VE) in internal combustion engine engineering is defined as the ratio of the equivalent volume of the fresh air drawn into the cylinder during the intake stroke (if the gases were at the reference condition for density) to the volume of the cylinder itself.
In order to keep the wind moving through the turbine, there has to be some wind movement, however small, on the other side with some wind speed greater than zero. Betz's law shows that as air flows through a certain area, and as wind speed slows from losing energy to extraction from a turbine, the airflow must distribute to a wider area.
The Carnot cycle is a cycle composed of the totally reversible processes of isentropic compression and expansion and isothermal heat addition and rejection. The thermal efficiency of a Carnot cycle depends only on the absolute temperatures of the two reservoirs in which heat transfer takes place, and for a power cycle is: