Adiabaticity index

Simple thermodynamic treatment of gas compression stipulates that the maximum temperature (Tmax) attained is dependent on the adiabatic index (y) of the gas ... 

From Table I one can conclude that within reasonable ranges for Kq (Z/A) and the adiabatic index T, prompt explosion energies can describe SN1987a or perhaps even more energetic supernovae. A close examination of the work of Shigeyama, Nomoto and Hashimoto [12] leads me to suspect they may have underestimated the energy in 1987a. 

The general character of the motion is shown in Fig. 1. A shock wave propagates in an unperturbed cold gas the maximum compression, which is dependent on the adiabatic index of the gas, is reached at the front of this wave. The velocity of propagation of the shock wave and the mass velocity at the front are related in an elementary way to the pressure of the shock wave. Behind the front the pressure, density, and velocity decrease.1... 

It is easy to see without calculation that, with time, I1 should increase and E2 should decrease. Thus, we are able in advance, before integration of the equations, and for any adiabatic index, to show that... 

A self-similar solution is found in which the pressure II at the shock wave front propagating in the gas decreases as a power function of the distance traveled, X II X n, where 1 < n < 2. In the general form, for any adiabatic index of the gas, it is proved that 1 < n < 2 for 7 = 7/5 the numerical value of n is 1.333. The law found yields the greatest possible rate of the plane shock wave decay under any circumstances. 

The existence of two types of self-similar solutions, explicitly formulated by Ya.B. for the first time, stimulated extensive studies to clarify the general character of the difference between them and to apply the concept of self-similar solutions of the second kind to various problems in mathematical physics. The present state of the problem can be found in a monograph by G. I. Barenblatt.6 We note also the existence of an exact analytic solution with a rational self-similarity exponent when the adiabatic index is equal to 7/5.7... 

The adiabatic index (y) is defined as the ratio of the specific heats of the gas measured at constant pressure (Cp) to that measured at constant volume (Cv). 

Given in paper [3.27] in graphical form are values [calculated by Eq. (3.7)] of the speed of sound and the adiabatic index (isentropic) kp for superheated vapors of Freon-22 at a pressure up to 6 MPa. Later, in the work of U. P. Aleshin and coworkers [0.1], diagrams of vv-T and kp -T for the same region of state were published. The calculations were carried out from an equation of state of type (0.7), where r = 9, 5, = 3, and 2, = 24. The equation was not tested, and the region of its applicability and composition of the initial experimental data were not specified. 

Pr Prandtl number a surface tension, Pa-m adiabatic index... 

The adiabatic gradient Vad = (F — 1)/ F, F is the adiabatic index. If this criterion is satisfied, the radiative temperature-pressure profile can be obtained if not, the pressure-temperature profile follows an adiabate. 

Determine the adiabatic index y of partly dissociated nitrogen gas if its dissociation ratio is a = 0.2. 

A gas mixture consists of an equal number of moles of argon and oxygen. Determine the adiabatic index y. 

Determine the dissociation rate a of the partly dissociated chlorine gas if the adiabatic index is y = (CpICy) = 1.48. 

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