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Figure 1. 

Nonreactive pressure traces of argon at 20 bar with an initial temperature T₁ of 40 °C in the driven section at the different tested temperatures T₅ ranging from 940 to 1,800 K.

Figure 2. 

Impact of the initial temperature in the driven section on the increase in pressure in argon. The mean pressure gradient dp*/dt was determined according to the work of Hargis et al.^[23]. The graphs show the normalized pressure traces with an initial temperature T₁ of 40 °C (in blue) and 80 °C (in green) at (a) low, (b) intermediate, and (c) high temperatures. (d) Linear fit of the experimental data.

Figure 3. 

Impact of the dioxygen concentration in argon on the pressure increase. The mean pressure gradient was determined according to the work of Hargis et al.^[23] The normalized pressure traces of the mixtures with 100% argon (in red), 10% O₂/90% argon (in green), and 25% O₂/75% argon (in blue) at (a)low, (b) intermediate, and (c) high temperatures. (d) Linear fit of the experimental data.

Figure 4. 

Steps for using (a) the argon pressure trace at initial conditions of 938 K and 21.2 bar behind the reflected shock wave and (b) its variation for developing a correction table for (c) volume or for (d) internal energy for kinetic models.

Figure 5. 

Application of the VTIM and QPRO methods for predicting the ignition delay time of CPT/O₂/Ar. (a) The ignition delay time of CPT at 20 bar and the equivalent ratio φ = 1. (b) The temperature as a function of time for the assumptions of a constant volume and internal energy (UV), a constant internal energy and variable volume (VTIM), and a constant volume and variable internal energy (QPRO) from the non-reactive pressure trace of argon at an initial temperature of 40 °C and the conditions behind the reflected shock wave of 938 K and 21.2 bar.

Figure 6. 

Ignition delay times of cyclopentane at 20 bar and temperatures from 930 to 1,700 K in O₂ and argon (CPT/O₂/Ar) for equivalence ratios (φ) of (a) 0.50, (b) 1.00, and (c) 2.00 at 1% and (d) 0.42, (e) 0.83, and (f) 1.67 at 2% fuel concentrations and the combustion kinetic model of cyclopentane with the ignition delay times computed by Do et al.^[14], with the variable volume approach and the heat transfer approach. Exp, experimental data from Do et al.^[14]. Lines, dashed lines, and dash-dot lines are the predicted ignition delay times.

Figure 7. 

Ignition delay times of tetrahydrofuran at 20 bar and temperatures from 865 to 1,570 K in O₂ and argon (THF/O₂/Ar) for equivalence ratios of (a) 0.5, (b) 1.0, and (c) 2.0 at 1% and (d) 0.44, (e) 0.88, and (f) 1.76 at 2% fuel concentrations and the combustion kinetic model of tetrahydrofuran with the ignition delay times computed by Do et al.^[14], with the variable volume approach and the heat transfer approach. Exp, experimental data from Do et al.^[14]. Lines, dashed lines, and dash-dot lines are the predicted ignition delay times.

Figure 8. 

Ignition delay times of pyrrolidine at 20 bar and temperatures ranging from 840 to 1,400 K in O₂ and argon (THP/O₂/Ar) for equivalence ratios of 0.5, 1.0, and 2.0 in fuel concentrations of 1% and 2% and temperatures ranging from 840 to 1,400 K and the combustion kinetic model of pyrrolidine with the ignition delay times computed by Goldsborough et al.^[15], with the variable volume approach and the heat transfer approach. Exp, experimental data from Goldsborough et al.^[15]. Lines, dashed lines, and dash-dot lines are the predicted ignition delay times.