Air Standard Efficiency for Petrol engines Calculator

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✖Compression ratio refers to how much the air-fuel mixture is squeezed in the cylinder before ignition. It's essentially the ratio between the volume of the cylinder at BDC to TDC.ⓘ Compression Ratio [r]			+10% -10%
✖The Heat Capacity Ratio or, adiabatic index quantifies the relationship between heat added at constant pressure and the resulting temperature increase compared to heat added at constant volume.ⓘ Heat Capacity Ratio [γ]			+10% -10%

✖Efficiency of otto cycle describes the maximum theoretical effectiveness of a petrol engine using air as working medium. It compares the work output to the heat input.ⓘ Air Standard Efficiency for Petrol engines [η_o]

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Formula

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Air Standard Efficiency for Petrol engines

Formula

`"η"_{"o"} = 100*(1-1/("r"^("γ"-1)))`

Example

`"69.82912"=100*(1-1/(("20")^("1.4"-1)))`

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Air Standard Efficiency for Petrol engines Solution

STEP 0: Pre-Calculation Summary

Formula Used

Efficiency of Otto Cycle = 100*(1-1/(Compression Ratio^(Heat Capacity Ratio-1)))
η_o = 100*(1-1/(r^(γ-1)))
This formula uses 3 Variables

Variables Used

Efficiency of Otto Cycle - Efficiency of otto cycle describes the maximum theoretical effectiveness of a petrol engine using air as working medium. It compares the work output to the heat input.
Compression Ratio - Compression ratio refers to how much the air-fuel mixture is squeezed in the cylinder before ignition. It's essentially the ratio between the volume of the cylinder at BDC to TDC.
Heat Capacity Ratio - The Heat Capacity Ratio or, adiabatic index quantifies the relationship between heat added at constant pressure and the resulting temperature increase compared to heat added at constant volume.

STEP 1: Convert Input(s) to Base Unit

Compression Ratio: 20 --> No Conversion Required
Heat Capacity Ratio: 1.4 --> No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

η_o = 100*(1-1/(r^(γ-1))) --> 100*(1-1/(20^(1.4-1)))

Evaluating ... ...

η_o = 69.8291183172742

STEP 3: Convert Result to Output's Unit

69.8291183172742 --> No Conversion Required

FINAL ANSWER

69.8291183172742 ≈ 69.82912 <-- Efficiency of Otto Cycle

(Calculation completed in 00.005 seconds)

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Created by Aditya Prakash Gautam

Indian Institute of Technology (IIT (ISM) ), Dhanbad, Jharkhand

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< 18 Air-Standard Cycles Calculators

Mean Effective Pressure in Dual Cycle

Go Mean Effective Pressure of Dual Cycle = Pressure at Start of Isentropic Compression*(Compression Ratio^Heat Capacity Ratio*((Pressure Ratio in Dual Cycle-1)+Heat Capacity Ratio*Pressure Ratio in Dual Cycle*(Cut-off Ratio-1))-Compression Ratio*(Pressure Ratio in Dual Cycle*Cut-off Ratio^Heat Capacity Ratio-1))/((Heat Capacity Ratio-1)*(Compression Ratio-1))

Thermal Efficiency of Stirling Cycle given Heat Exchanger Effectiveness

Go Thermal Efficiency of Stirling Cycle = 100*(([R]*ln(Compression Ratio)*(Final Temperature-Initial Temperature))/([R]*Final Temperature*ln(Compression Ratio)+Molar Specific Heat Capacity at Constant Volume*(1-Effectiveness of Heat Exchanger)*(Final Temperature-Initial Temperature)))

Work Output for Dual Cycle

Go Work Output of Dual Cycle = Pressure at Start of Isentropic Compression*Volume at Start of Isentropic Compression*(Compression Ratio^(Heat Capacity Ratio-1)*(Heat Capacity Ratio*Pressure Ratio*(Cut-off Ratio-1)+(Pressure Ratio-1))-(Pressure Ratio*Cut-off Ratio^(Heat Capacity Ratio)-1))/(Heat Capacity Ratio-1)

Work Output for Diesel Cycle

Go Work Output of Diesel Cycle = Pressure at Start of Isentropic Compression*Volume at Start of Isentropic Compression*(Compression Ratio^(Heat Capacity Ratio-1)*(Heat Capacity Ratio*(Cut-off Ratio-1)-Compression Ratio^(1-Heat Capacity Ratio)*(Cut-off Ratio^(Heat Capacity Ratio)-1)))/(Heat Capacity Ratio-1)

Mean Effective Pressure in Diesel Cycle

Go Mean Effective Pressure of Diesel Cycle = Pressure at Start of Isentropic Compression*(Heat Capacity Ratio*Compression Ratio^Heat Capacity Ratio*(Cut-off Ratio-1)-Compression Ratio*(Cut-off Ratio^Heat Capacity Ratio-1))/((Heat Capacity Ratio-1)*(Compression Ratio-1))

Thermal Efficiency of Dual Cycle

Go Thermal Efficiency of Dual Cycle = 100*(1-1/(Compression Ratio^(Heat Capacity Ratio-1))*((Pressure Ratio in Dual Cycle*Cut-off Ratio^Heat Capacity Ratio-1)/(Pressure Ratio in Dual Cycle-1+Pressure Ratio in Dual Cycle*Heat Capacity Ratio*(Cut-off Ratio-1))))

Mean Effective Pressure in Otto Cycle

Go Mean Effective Pressure of Otto Cycle = Pressure at Start of Isentropic Compression*Compression Ratio*(((Compression Ratio^(Heat Capacity Ratio-1)-1)*(Pressure Ratio-1))/((Compression Ratio-1)*(Heat Capacity Ratio-1)))

Thermal Efficiency of Atkinson Cycle

Go Thermal Efficiency of Atkinson Cycle = 100*(1-Heat Capacity Ratio*((Expansion Ratio-Compression Ratio)/(Expansion Ratio^(Heat Capacity Ratio)-Compression Ratio^(Heat Capacity Ratio))))

Work Output for Otto Cycle

Go Work Output of Otto Cycle = Pressure at Start of Isentropic Compression*Volume at Start of Isentropic Compression*((Pressure Ratio-1)*(Compression Ratio^(Heat Capacity Ratio-1)-1))/(Heat Capacity Ratio-1)

Air Standard Efficiency for Diesel Engines

Go Efficiency of Diesel Cycle = 100*(1-1/(Compression Ratio^(Heat Capacity Ratio-1))*(Cut-off Ratio^(Heat Capacity Ratio)-1)/(Heat Capacity Ratio*(Cut-off Ratio-1)))

Thermal Efficiency of Diesel Cycle

Go Thermal Efficiency of Diesel Cycle = 1-1/Compression Ratio^(Heat Capacity Ratio-1)*(Cut-off Ratio^Heat Capacity Ratio-1)/(Heat Capacity Ratio*(Cut-off Ratio-1))

Thermal Efficiency of Lenoir Cycle

Go Thermal Efficiency of Lenoir Cycle = 100*(1-Heat Capacity Ratio*((Pressure Ratio^(1/Heat Capacity Ratio)-1)/(Pressure Ratio-1)))

Thermal Efficiency of Ericsson Cycle

Go Thermal Efficiency of Ericsson Cycle = (Higher Temperature-Lower Temperature)/(Higher Temperature)

Air Standard Efficiency for Petrol engines

Go Efficiency of Otto Cycle = 100*(1-1/(Compression Ratio^(Heat Capacity Ratio-1)))

Thermal Efficiency of Otto Cycle

Go Thermal Efficiency of Otto Cycle = 1-1/Compression Ratio^(Heat Capacity Ratio-1)

Relative Air-Fuel Ratio

Go Relative Air Fuel Ratio = Actual Air Fuel Ratio/Stoichiometric Air Fuel Ratio

Air Standard Efficiency given Relative Efficiency

Go Efficiency = Indicated Thermal Efficiency/Relative Efficiency

Actual Air Fuel Ratio

Go Actual Air Fuel Ratio = Mass of Air/Mass of Fuel

Air Standard Efficiency for Petrol engines Formula

Efficiency of Otto Cycle = 100*(1-1/(Compression Ratio^(Heat Capacity Ratio-1)))
η_o = 100*(1-1/(r^(γ-1)))

What are the theoretical processes involved in the otto cycle?

Isentropic Compression(1-2): Air-fuel mixture is compressed in the cylinder without heat transfer, raising pressure and temperature.
Constant Volume Heat Addition(2-3): Spark ignition causes the air-fuel mixture to combust rapidly at a constant volume, significantly increasing temperature.
Isentropic Expansion(3-4): The hot, high-pressure gas expands in the cylinder, performing work on the piston.
Constant Pressure Heat Rejection(4-1): Heat is removed from the cylinder at a constant pressure, lowering temperature and pressure back to its starting point.

How to Calculate Air Standard Efficiency for Petrol engines?

Air Standard Efficiency for Petrol engines calculator uses Efficiency of Otto Cycle = 100*(1-1/(Compression Ratio^(Heat Capacity Ratio-1))) to calculate the Efficiency of Otto Cycle, Air Standard Efficiency for Petrol engines represents the theoretical maximum efficiency a petrol engine could achieve under perfect conditions where working medium of the engine is considered as air. Real-world petrol engines experience friction, heat transfer, and incomplete combustion, leading to lower efficiencies. By analyzing this theoretical cycle, engineers can determine the maximum theoretical efficiency a petrol engine could achieve. This air standard efficiency serves as a benchmark for evaluating the performance of real petrol engines. Efficiency of Otto Cycle is denoted by η_o symbol.

How to calculate Air Standard Efficiency for Petrol engines using this online calculator? To use this online calculator for Air Standard Efficiency for Petrol engines, enter Compression Ratio (r) & Heat Capacity Ratio (γ) and hit the calculate button. Here is how the Air Standard Efficiency for Petrol engines calculation can be explained with given input values -> 20.0562 = 100*(1-1/(compsn_ratio_asc_ic^(1.4-1))).

FAQ

What is Air Standard Efficiency for Petrol engines?

Air Standard Efficiency for Petrol engines represents the theoretical maximum efficiency a petrol engine could achieve under perfect conditions where working medium of the engine is considered as air. Real-world petrol engines experience friction, heat transfer, and incomplete combustion, leading to lower efficiencies. By analyzing this theoretical cycle, engineers can determine the maximum theoretical efficiency a petrol engine could achieve. This air standard efficiency serves as a benchmark for evaluating the performance of real petrol engines and is represented as η_o = 100*(1-1/(r^(γ-1))) or Efficiency of Otto Cycle = 100*(1-1/(Compression Ratio^(Heat Capacity Ratio-1))). Compression ratio refers to how much the air-fuel mixture is squeezed in the cylinder before ignition. It's essentially the ratio between the volume of the cylinder at BDC to TDC & The Heat Capacity Ratio or, adiabatic index quantifies the relationship between heat added at constant pressure and the resulting temperature increase compared to heat added at constant volume.

How to calculate Air Standard Efficiency for Petrol engines?

Air Standard Efficiency for Petrol engines represents the theoretical maximum efficiency a petrol engine could achieve under perfect conditions where working medium of the engine is considered as air. Real-world petrol engines experience friction, heat transfer, and incomplete combustion, leading to lower efficiencies. By analyzing this theoretical cycle, engineers can determine the maximum theoretical efficiency a petrol engine could achieve. This air standard efficiency serves as a benchmark for evaluating the performance of real petrol engines is calculated using Efficiency of Otto Cycle = 100*(1-1/(Compression Ratio^(Heat Capacity Ratio-1))). To calculate Air Standard Efficiency for Petrol engines, you need Compression Ratio (r) & Heat Capacity Ratio (γ). With our tool, you need to enter the respective value for Compression Ratio & Heat Capacity Ratio and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

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