Propellant Flow Actuated Piezoelectric Rocket Engine Igniter

Spark ignition of a bi-propellant rocket engine is a classic, proven, and generally reliable process. However, timing can be critical, and the control logic, additional electronic components and wiring adds complexity, cost and weight. These factors can be especially undesirable for small attitude or reaction control engines. The proposed innovation uses a novel method to excite a piezo-ceramic crystal using the initiation of propellant flow to the engine. When the propellant valves are opened, the precise timing of the spark relative to propellant flow, as well as the flow start transient, are governed by the geometry of the device. Hence, precise, repeatable start conditions should be achieved with no additional control logic or complexity. Furthermore, the piezo-ceramic crystal is integral to (and embedded in) the igniter body, thereby completely eliminating external wiring and associated complexity. A bench-top demonstration of one manifestation of the device (incorporating only one very simple moving part) has already demonstrated basic feasibility. Other manifestations with no moving parts what-so-ever (at the macroscopic scale) may also be viable, and will be investigated. Phase 1 TLR advancement goal is from 3 to 5, with Phase 2 goal of 7.