Diesel Engine Prob: Formula for Temp at Stages 3 & 4

In summary, for an air standard cycle using Diesel fuel, the formula for calculating the temperature at state 3 is T3 = T2 + (Q1 / (m * cp)), where Q1 is the heat input, T2 is the temperature at cycle 2, m is the mass, and cp is the specific heat of gas at constant pressure. To find the temperature at state 4, you will need the compression ratios at states 3 and 4, the adiabatic constant of air (k), and the temperature at state 3. The formula for state 4 is T4 = T3 * (V3/V4) ^ (k-1), where T3 is the temperature at state
  • #1
waterboy312
1
0
how would you find the correct formula for the temp at state 3 and 4. i found it for 1 and 2
 
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  • #2
Hello Waterboy.

First, I would ask that when you have a question try to be specific and do not abbreviate the words, because many members here are from different countries and areas.

For an air standard cycle, whose fuel is Diesel:

To calculate the temperature in the cycle expansion (3), it will be the point of greatest pressure and higher temperature, use the formula:


T3 = T2 + (Q1 / (m * cp);

where:

Q1 = heat input
T2 = temperature cycle 2
m = mass
cp = specific heat of gas at constant pressure

To obtain the temperature in the cycle of the removal of heat (4) you must have the values of compression ratio in cycles 3 (V3) and 4 (V4) and the adiabatic constant of air (k), and the temperature in the expansion cycle (3).



T4 = T3 * (V3/V4) ^ (k-1);

where:

T3 = temperature in cycle 3
V3 = volume in the cycle 3
V4 = volume in the cycle 4
k = constant adiabatic air



If you have any questions about the theory of everything, or to obtain Q1 or mass simply send an email. I am new in this form too and do not know to use mathematical symbols, if someone can explain me please tell me.

I hope this can help.
 

1. What is a diesel engine and how does it work?

A diesel engine is a type of internal combustion engine that uses compression ignition to ignite the fuel, rather than a spark. In this process, air is compressed within the engine's cylinder, causing it to heat up. Fuel is then injected into the cylinder, where it reacts with the hot air, causing combustion and powering the engine.

2. What are the stages of a diesel engine?

A diesel engine typically has four stages: intake, compression, power, and exhaust. During the intake stage, air is drawn into the cylinder. In the compression stage, the air is compressed, causing it to heat up. The power stage is where fuel is injected and combustion occurs, providing energy to power the engine. Finally, the exhaust stage releases the waste gases from the combustion process.

3. What is the formula for calculating temperature at stages 3 and 4 in a diesel engine?

The formula for calculating temperature at stages 3 and 4 is T = P * V / (n * R), where T is the temperature in Kelvin, P is the pressure in atmospheres, V is the volume in liters, n is the number of moles of gas, and R is the ideal gas constant. This formula uses the ideal gas law to calculate the temperature of the air-fuel mixture in the cylinder during the power and exhaust stages.

4. Why is it important to know the temperature at stages 3 and 4 in a diesel engine?

Knowing the temperature at stages 3 and 4 is important for several reasons. First, it helps to ensure that the air-fuel mixture is at the optimal temperature for combustion, which will result in better performance and efficiency. Additionally, it can help identify any potential issues with the engine, such as overheating or inefficient combustion.

5. How can the temperature at stages 3 and 4 be controlled in a diesel engine?

The temperature at stages 3 and 4 can be controlled through various methods, such as adjusting the air-fuel ratio, changing the compression ratio, and improving the engine's cooling system. Additionally, using higher quality fuels and maintaining proper engine maintenance can also help to control the temperature at these stages.

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