Adiabatic coefficient

Compressibility must be taken into account along with the adiabatic coefficient, k, (or, if known, the polytropic coefficient, n) and other losses, which will be presented in the following paragraphs. 

To obtain a similar expression for Nk t), we introduce binned adiabatic coefficients cik t), that is,... 

Compression of hydrogen consumes energy depending on the thermodynamic process. The ideal isothermal compression requires the least amount of energy (just compression work) and the adiabatic process requires the maximum amount of energy. The compression energy W depends on the initial pressure p and the final pressure pf, the initial volume V and the adiabatic coefficient y ... 

Figure 7.1-12. Energy stored in a gas pressurised vessel as function of pressure and the energy equivalent in mass of TNT according to a volume of 1 fit3 and a gas with an adiabatic coefficient c = 1.66 (Argon). Argon data are based on the Redlich-Kwong - Equation of State. These curves should only be used as a guide. Variation of temperature within a vessel must be considered [19],...

Let us in the following derive a relation between the actual transmission coefficient, gh, and the non-adiabatic coefficient, Kna, since it will show why gh > na and which part of the power spectrum for the solvent motion that is responsible for this. We see from Eq. (11.87) that... 

Where P is standard atmospheric pressure P is actual pressure of the gas and k is adiabatic coefficient of the gas. 

Adiabatic coefficient of methane k is 1.32, substituting into formula (7) and (8) in the calculation, the critical value of P is 1.8P . Due to the current long-distance natural gas transportation pipeline design pressure is above 6 MPa, and its work pressure is greater than 1.8P so its flow is sonic flow, and the leak rate is calculated according to the following formula (SINOPEC Safety Engineering Institute 2007). 

Example 7.2.2 This can be seen, when solving the truck example for different values of the adiabatic coefficient k. When k exceeds a value between 1,542 and 1.545, the relative translation p o changes its sign. This leads to the physically unrealistic situation shown in Fig. 7.2. Although technically irrelevant, these values of K can occur within the optimization loop as intermediate results. 

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