Table 3.
Comparison between the numerical impulse and the impulse of fitted Friedlander form. The initial pressure is the pressure in the driver section before the membrane bursts and the shock pressure ratio is the ratio between the pick overpressure and the ambient pressure.
| initial pressure (kPa) | 234.0 |
440.0 |
||||||
|---|---|---|---|---|---|---|---|---|
| shock pressure ratio (p2−p1)/p1 | 0.5 |
1.0 |
||||||
| driver length (m) | 0.25 | 0.50 | 0.75 | 1.00 | 0.25 | 0.50 | 0.75 | 1.0 |
| impulse | ||||||||
| numerical (Pa s) | 84.2 | 170.5 | 256.9 | 346.4 | 201.6 | 409.0 | 613.4 | 823.7 |
| fitted (Pa s) | 84.0 | 170.4 | 256.5 | 345.8 | 201.0 | 408.0 | 612.0 | 822.0 |
| error (%) | 0.1 | 0.1 | 0.1 | 0.2 | 0.3 | 0.3 | 0.2 | 0.2 |
| initial pressure (kPa) | 1153.1 |
2452.8 |
||||||
|---|---|---|---|---|---|---|---|---|
| shock pressure ratio (p2−p1)/p1 | 2.0 |
3.0 |
||||||
| driver length (m) | 0.25 | 0.50 | 0.75 | 1.00 | 0.25 | 0.50 | 0.75 | 1.00 |
| impulse | ||||||||
| numerical (Pa s) | 562.8 | 1140.6 | 1711.0 | 2281.2 | 1174.8 | 2348.6 | 3509.1 | 4700.1 |
| fitted (Pa s) | 558.3 | 1131.4 | 1697.5 | 2263.4 | 1153.8 | 2306.0 | 3446.5 | 4614.8 |
| error (%) | 0.8 | 0.8 | 0.8 | 0.8 | 1.8 | 1.8 | 1.8 | 1.8 |