Recently, [Integza] has experimented with various jet engines, from pulsejets to jet engines. Previously, efforts were focused on increasing fuel intake or using forced air intakes. However, now there is a shift towards refining the concept by exploring the controllable detonation engine. In the most recent experiment (watch the video below), the objective is to fine-tune the concept further. Initially, a prototype was constructed using resin printed components, tubing, gas control valves, and a long acrylic tube for directing the exhaust. Control over butane and air injection, along with the ignition spark, is managed by an Arduino—although a 555 timer could have been used instead—powering several solid-state relays. This setup allowed for consistent control of the pulse rate. The aim is to develop a rotating detonation engine, which presents an intriguing engine design. It will be fascinating to observe whether it can be successfully operationalized.
Detonation engines harness the thrust generated from pressure, with emphasis on detonative combustion. This combustion process occurs at a constant pressure, theoretically resulting in higher efficiency compared to traditional deflagration. However, the associated risks are amplified. Achieving this with a fuel/air mixture can be challenging as the mix lacks the required power. To address this, [Integza] experimented with incorporating a Shchelkin spiral (referred to as springs) to slow down combustion and reduce the transition time from deflagration to detonation.
While this modification showed some success, it wasn’t sufficient, prompting a shift towards using butane and pure oxygen. This confirmed the validity of the core concept. The final phase involved rebuilding the entire setup using metal components, including CNC machined end plates and box sections fastened with bolts. This revision demonstrated relatively successful operation at approximately 10 pulses per second, generating measurable thrust, albeit not significant. There is more refinement required for optimal performance.
Earlier experiments involved forced-air pulsejets, an area of focus worth exploring. Additionally, in the realm of pulsejets, the noteworthy project of [Colinfurze] and his pulsejet go-kart should not go unmentioned.
Image Source: Hackaday
