Initiation of heterogeneous detonation in tubes with coils and Shchelkin spiral

Abstract

The possibilities of significant reduction of the critical energy of initiation of detonation in sprays of liquid hydrocarbon fuel in air are demonstrated experimentally. The structure developed for the purpose includes a tube of near-limiting diameter and a combination of Shchelkin spiral, tube coils, and reducing cones for transitioning a detonation wave to a tube of large diameter.

Detonation initiation techniques for pulse detonation propulsion

“…As a matter of fact, the experimental and computational studies described in this section demonstrate that fast DDT can be facilitated by placing a tube coil on the way of the propagating shock wave. Shchelkin spiral and tube coil [19,20]. Dimensions are in millimeters Figure 4 shows the schematic of the tube 36 mm in diameter equipped with the air-assist atomizer A, electrical igniter ED, Shchelkin spiral and removable coil section with the coil length along the tube axis equal to 255 mm [19,20].…”

“…Shchelkin spiral and tube coil [19,20]. Dimensions are in millimeters Figure 4 shows the schematic of the tube 36 mm in diameter equipped with the air-assist atomizer A, electrical igniter ED, Shchelkin spiral and removable coil section with the coil length along the tube axis equal to 255 mm [19,20]. A similar setup with a tube 28 mm in diameter was also used in the experiments.…”

“…The detonation wave propagated toward the end of the tube with the constant mean velocity. Fast DDT is solely 328 PULSED/CONTINUOUS DETONATION PROPULSION Figure 5 Pressure records in the run with low ignition energy [19,20] attributed to the use of the coil. Multiple re §ections of the shock wave from the compressive surfaces inside the coil facilitate detonation initiation.…”