Fast-Acting Valves for Use in Shock Tubes : Part 1, Construction and Their Characteristics

Design of a fast diaphragmless shock tube driver

“…Ikui et al [13,14] developed two kinds of fast-acting valves based on pneumatic actuators. The researchers substituted the diaphragm for either a piston that opens axially or a gate that opens transversally with respect to the main axis of the shock tube.…”

“…For example, while diaphragms take typically 0.2-0.5 ms to rupture [14,18], the opening time of axial pistons could vary from 0.9 ms to around 97 ms, depending mainly on their configuration, weight, and actuating pressure. Customized pneumatic actuators can exhibit opening times within the lower range of this time interval (0.9-2.4 ms) [13,14,25], while commercial actuators tend to perform in the upper range (27-97 ms) [7]. For the same actuating mechanism, transversal gates can take six times as long to open, because their effective opening distance is larger than that of axial pistons (see reference [13], for more details).…”

“…Customized pneumatic actuators can exhibit opening times within the lower range of this time interval (0.9-2.4 ms) [13,14,25], while commercial actuators tend to perform in the upper range (27-97 ms) [7]. For the same actuating mechanism, transversal gates can take six times as long to open, because their effective opening distance is larger than that of axial pistons (see reference [13], for more details). In an effort to reduce the opening time of transversal gates, Abe et al [1] implemented two opposing pistons in place of a single transversal gate, allowing them to reduce the opening time to around 1.79 ms for a tube with a diameter of 40 mm.…”