Ram Efficiency Calculator

✖Stagnation Pressure of System is the pressure at the stagnation temperature during the process of ramming.ⓘ Stagnation Pressure of System [p₂']			+10% -10%
✖Initial Pressure of System is the total initial pressure exerted by the molecules inside the system.ⓘ Initial Pressure of System [P_i]			+10% -10%
✖Final Pressure of System is the total final pressure exerted by the molecules inside the system.ⓘ Final Pressure of System [P_f]			+10% -10%

✖Ram efficiency is defined as the ratio of the actual rise in pressure and isentropic rise in static pressure.ⓘ Ram Efficiency [η]

⎘ Copy

👎

Formula

✖

Ram Efficiency

Formula

`"η" = (("p"_{"2"}"'")-"P"_{"i"})/("P"_{"f"}-"P"_{"i"})`

Example

`"0.866667"=("150000Pa"-"85000Pa")/("160000Pa"-"85000Pa")`

Calculator

LaTeX

Reset

👍

Download Refrigeration and Air Conditioning Formulas PDF PDF Image

Ram Efficiency Solution

STEP 0: Pre-Calculation Summary

Formula Used

Ram Efficiency = (Stagnation Pressure of System-Initial Pressure of System)/(Final Pressure of System-Initial Pressure of System)
η = (p₂'-P_i)/(P_f-P_i)
This formula uses 4 Variables

Variables Used

Ram Efficiency - Ram efficiency is defined as the ratio of the actual rise in pressure and isentropic rise in static pressure.
Stagnation Pressure of System - (Measured in Pascal) - Stagnation Pressure of System is the pressure at the stagnation temperature during the process of ramming.
Initial Pressure of System - (Measured in Pascal) - Initial Pressure of System is the total initial pressure exerted by the molecules inside the system.
Final Pressure of System - (Measured in Pascal) - Final Pressure of System is the total final pressure exerted by the molecules inside the system.

STEP 1: Convert Input(s) to Base Unit

Stagnation Pressure of System: 150000 Pascal --> 150000 Pascal No Conversion Required
Initial Pressure of System: 85000 Pascal --> 85000 Pascal No Conversion Required
Final Pressure of System: 160000 Pascal --> 160000 Pascal No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

η = (p₂'-P_i)/(P_f-P_i) --> (150000-85000)/(160000-85000)

Evaluating ... ...

η = 0.866666666666667

STEP 3: Convert Result to Output's Unit

0.866666666666667 --> No Conversion Required

FINAL ANSWER

0.866666666666667 ≈ 0.866667 <-- Ram Efficiency

(Calculation completed in 00.004 seconds)

You are here -

Home » Engineering » Mechanical » Refrigeration and Air Conditioning » Air Refrigeration Systems » Ram Efficiency

Credits

Created by Rushi Shah

K J Somaiya College of Engineering (K J Somaiya), Mumbai

Rushi Shah has created this Calculator and 25+ more calculators!

Verified by Venkata Sai Prasanna Aradhyula

Birla Institute of Technology & Science (BITS), Hyderabad

Venkata Sai Prasanna Aradhyula has verified this Calculator and 10+ more calculators!

< 4 Air Refrigeration Systems Calculators

Temperature Ratio at Start and End of Ramming Process

Go Temperature Ratio = 1+(Velocity^2*(Heat Capacity Ratio-1))/(2*Heat Capacity Ratio*[R]*Initial Temperature)

Ram Efficiency

Go Ram Efficiency = (Stagnation Pressure of System-Initial Pressure of System)/(Final Pressure of System-Initial Pressure of System)

Local Sonic or Acoustic Velocity at Ambient Air Conditions

Go Sonic Velocity = (Heat Capacity Ratio*[R]*Initial Temperature/Molecular Weight)^0.5

Initial Mass of Evaporant Required to be Carried for given Flight Time

Go Mass = (Rate of Heat Removal*Time in Minutes)/Latent Heat of Vaporization

< 17 Air Refrigeration Systems Calculators

Power required to maintain pressure inside cabin excluding ram work

Go Input Power = ((Mass of Air*Specific Heat Capacity at Constant Pressure*Actual temperature of Rammed Air)/(Compressor Efficiency))*((Cabin Pressure/Pressure of Rammed Air)^((Heat Capacity Ratio-1)/Heat Capacity Ratio)-1)

Power Required to Maintain Pressure inside Cabin including Ram Work

Go Input Power = ((Mass of Air*Specific Heat Capacity at Constant Pressure*Ambient Air Temperature)/(Compressor Efficiency))*((Cabin Pressure/Atmospheric Pressure)^((Heat Capacity Ratio-1)/Heat Capacity Ratio)-1)

C.O.P. of simple air evaporative cycle

Go Actual Coefficient of Performance = (210*Tonnage of Refrigeration in TR)/(Mass of Air*Specific Heat Capacity at Constant Pressure*(Actual End Temp of Isentropic Compression-Actual temperature of Rammed Air))

C.O.P. of simple air cycle

Go Actual Coefficient of Performance = (Inside temperature of cabin-Actual temperature at end of isentropic expansion)/(Actual End Temp of Isentropic Compression-Actual temperature of Rammed Air)

Mass of air to produce Q tonnes of refrigeration given exit temperature of cooling turbine

Go Mass of Air = (210*Tonnage of Refrigeration in TR)/(Specific Heat Capacity at Constant Pressure*(Temperature at End of Isentropic Expansion-Actual exit Temperature of cooling turbine))

Mass of air to produce Q tonnes of refrigeration

Go Mass of Air = (210*Tonnage of Refrigeration in TR)/(Specific Heat Capacity at Constant Pressure*(Inside temperature of cabin-Actual temperature at end of isentropic expansion))

Expansion Work

Go Work Done per min = Mass of Air*Specific Heat Capacity at Constant Pressure*(Temperature at the end of cooling process-Actual temperature at end of isentropic expansion)

Refrigeration Effect Produced

Go Refrigeration Effect Produced = Mass of Air*Specific Heat Capacity at Constant Pressure*(Inside temperature of cabin-Actual temperature at end of isentropic expansion)

Heat rejected during cooling process

Go Heat Rejected = Mass of Air*Specific Heat Capacity at Constant Pressure*(Actual End Temp of Isentropic Compression-Temperature at the end of cooling process)

Compression Work

Go Work Done per min = Mass of Air*Specific Heat Capacity at Constant Pressure*(Actual End Temp of Isentropic Compression-Actual temperature of Rammed Air)

Power Required for Refrigeration System

Go Input Power = (Mass of Air*Specific Heat Capacity at Constant Pressure*(Actual End Temp of Isentropic Compression-Actual temperature of Rammed Air))/60

Temperature Ratio at Start and End of Ramming Process

Go Temperature Ratio = 1+(Velocity^2*(Heat Capacity Ratio-1))/(2*Heat Capacity Ratio*[R]*Initial Temperature)

Ram Efficiency

Go Ram Efficiency = (Stagnation Pressure of System-Initial Pressure of System)/(Final Pressure of System-Initial Pressure of System)

Local Sonic or Acoustic Velocity at Ambient Air Conditions

Go Sonic Velocity = (Heat Capacity Ratio*[R]*Initial Temperature/Molecular Weight)^0.5

Initial Mass of Evaporant Required to be Carried for given Flight Time

Go Mass = (Rate of Heat Removal*Time in Minutes)/Latent Heat of Vaporization

COP of Air Cycle for given Input Power and Tonnage of Refrigeration

Go Actual Coefficient of Performance = (210*Tonnage of Refrigeration in TR)/(Input Power*60)

COP of Air Cycle given Input Power

Go Actual Coefficient of Performance = (210*Tonnage of Refrigeration in TR)/(Input Power*60)

Ram Efficiency Formula

Ram Efficiency = (Stagnation Pressure of System-Initial Pressure of System)/(Final Pressure of System-Initial Pressure of System)
η = (p₂'-P_i)/(P_f-P_i)

What is Ram efficiency?

Ram efficiency is defined as the ratio of the actual rise in pressure and isentropic rise in static pressure.

How to Calculate Ram Efficiency?

Ram Efficiency calculator uses Ram Efficiency = (Stagnation Pressure of System-Initial Pressure of System)/(Final Pressure of System-Initial Pressure of System) to calculate the Ram Efficiency, Ram Efficiency is defined as the isentropic pressure rise. It is defined as the ratio of actual total temperature rise to the ideal total temperature rise. Ram Efficiency is denoted by η symbol.

How to calculate Ram Efficiency using this online calculator? To use this online calculator for Ram Efficiency, enter Stagnation Pressure of System (p₂'), Initial Pressure of System (P_i) & Final Pressure of System (P_f) and hit the calculate button. Here is how the Ram Efficiency calculation can be explained with given input values -> 0.866667 = (150000-85000)/(160000-85000).

FAQ

What is Ram Efficiency?

Ram Efficiency is defined as the isentropic pressure rise. It is defined as the ratio of actual total temperature rise to the ideal total temperature rise and is represented as η = (p₂'-P_i)/(P_f-P_i) or Ram Efficiency = (Stagnation Pressure of System-Initial Pressure of System)/(Final Pressure of System-Initial Pressure of System). Stagnation Pressure of System is the pressure at the stagnation temperature during the process of ramming, Initial Pressure of System is the total initial pressure exerted by the molecules inside the system & Final Pressure of System is the total final pressure exerted by the molecules inside the system.

How to calculate Ram Efficiency?

Ram Efficiency is defined as the isentropic pressure rise. It is defined as the ratio of actual total temperature rise to the ideal total temperature rise is calculated using Ram Efficiency = (Stagnation Pressure of System-Initial Pressure of System)/(Final Pressure of System-Initial Pressure of System). To calculate Ram Efficiency, you need Stagnation Pressure of System (p₂'), Initial Pressure of System (P_i) & Final Pressure of System (P_f). With our tool, you need to enter the respective value for Stagnation Pressure of System, Initial Pressure of System & Final Pressure of System and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

Home

FREE PDFs

🔍 Search