Evolution of pressure

Fig. 12 Symmetrization run for n-hexane. Left, the evolution of the overall asymmetry index (upper curve) and of the overall density (lower curve). Right the evolution of pressure (atm) and of intramolecular, intermolecular Lennard-Jones and total energy (kJ moP ). The abscissa shows the number of million MC moves, corresponding to a time of a few picoseconds...

Fig. 3. Evolution of pressure drop with inlet velocity. Comparison between data presented by Bohnet [2], the predictions of CFD and four empirical models (P = lbar, T = 293K, D = 150mm, geometry Bohnet [2]).

Figure 3.19 Evolution of pressure of the pump when slow clogging occurs.

Thermal conductivity, H/C ratio, specific volume and specific heat vary during the chemical evolution of the deposit. Unfortunately, there is very small quantity of data in the literature on thermal conductivity. In fact, what little there is refers to coke or bitumen and provides limited or sometimes contradictory information because of the high dependency on the structure and composition of the solid. More reliable data refer to disordered graphite, similar to an aged deposit, without hydrogen and with a low porosity. The available experimental data on the time evolution of pressure drop and tube metal temperature in pyrolysis coils of ethylene crackers only permit rough estimates of the overall and average thickness and thermal conductivity of the deposit. 

Figure 4. Evolution of pressure increase (AP) and catalyst temperature during 15 successive injections of composition of HAN79-H2O at 85 °C on °°Pt/Al203Si catalyst.

Figure 2 presents the evolution of pressure drop versus flow rate for each sample under consideration. The catalytic coating had a measurable effect on the permeability of most samples (a maximum reduction of about 40%) but this will not affect adversely their pressure drop under soot loading, since most of the pressure drop of the loaded filter comes from the soot cake built up on the wall. 

Figure 5 Evolution of pressure drop versus time for all samples during regeneration...

Figure 25. Measured evolution of pressure in first packer located in radial borehole SF 21 at a radial distance of 1.86 m. Also shown are predicted water pressures for a radial distance of 3.03 m.

If we look at the evolution of pressure in Fig. 6, we observe three distinct parts in one period (about 275 ms). The first consists of the decrease in pressure for approximately 150 ms from B to D. The average pressure decrease in C is 62 kPa/s, whereas in the second part the refilling of the liquid, with a duration of about 65 ms, corresponds to the D to A part on the curve. The average pressure increase in E is about 136 kPa/s. The third part between A and B flowing in the channel and slowing down accounts for only 60 ms of one period. 

The isochoric simulations for pure silica were conducted for fixed density values ranging between 2.97 and 4.2 g cm and for a temperature of 3000 K. The evolution of pressure as a function of density is given... 

FIG. 13. Evolution of pressure in the SA during pipe rupture event. 

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