Technical Applications

Utilizing precisely controlled injection of heated fuel up to supercritical state allows for improved mixing and cleaner combustion. Transonic Combustion products can be applied to meet a variety of technical applications. Below is a list of a few applications:

Compression Ignition in an Internal Combustion Engine with Gasoline

The supercritical injection of fuel enables cost-effective compression ignition of gasoline in engines with a conventional architecture. This is described as “Injection Ignition”, and it results in efficiencies that are equal to or better than modern Diesel engines.

The Transonic Combustion fuel injection system (TSCi™) addresses the major issues that limit the efficiency of the gasoline engine. It is capable of operating over a wide range of air/fuel ratios and so does not require a throttle for load control. Injection Ignition with TSCi™ has inherently short combustion delay and a fast combustion that combine in heat release phasing for optimal efficiency. An engine equipped with TSCi™ can be operated at an optimal compression ratio since it is not dependent on high octane gasoline.

Injection Ignition with TSCi™ is a new combustion process for the gasoline internal combustion engine which can provide over a 25% reduction in fuel consumption. This combustion process utilizes direct injection of supercritical fuel into the cylinder. Supercritical fuel promotes rapid mixing with the contents of the cylinder which, after a short delay, results in spontaneous ignition at multiple locations. Multiple ignition sites and rapid combustion combine to result in optimum heat release and high cycle efficiency. Other advantages are the elimination of droplet burning and increased combustion stability that results from multiple ignition sources.

Compression Ignition in an Internal Combustion Engine with Ethanol

In select markets, Ethanol is a major source of fuel. In combination with the Transonic Combustion catalytic process, the injection of supercritical fuel enables compression ignition of Ethanol in an internal combustion engine. Benefits include reduced fuel consumption and increased fuel efficiency. Additionally, heated injection reduces the need for additional equipment such as glow plugs and negates the need to add ‘anti-freeze’ agents to the Ethanol, thereby reducing operating costs.

Direct Injection in a Spark Ignited Engine with Gasoline

Application of the TSCi™ system to a traditional spark ignited gasoline direct injected engine results in a significant reduction of particle emissions and a reduced fuel consumption trend.

Heated fuel (in the form of a supercritical fluid) in a spark ignited engine can produce significantly lower emissions. Laboratory results have shown significant reductions in HydroCarbons (HC), Filter Smoke Number (FSN), Particulate Matter and Particle Count.

Due to efficient packaging and a patented heating design created by the Transonic Combustion team, the injector design is a drop in solution that can be applied to current production internal combustion engines. Additionally, this process serves as an enabler for stratified charge and homogenous charge combustion strategies.

Direct Injection in a Spark Ignited Engine with Jet Fuel

Implementation of the TSCi system enables the use of jet fuel in spark ignited engines.


A supercritical fluid is any substance at a temperature and pressure above its critical point; it is not a solid, liquid or a gas. Generally supercritical fluids have properties between those of a gas and a liquid. Supercritical fluids also have other unique properties such as having no surface tension, the ability to solvate other liquids and solids and the formation of small particles with a narrow size distribution during a phase change to liquid. Supercritical fluids possess rapid mass transfer properties with diffusion coefficients more than ten times that of a liquid near the critical point. The density ranges between one third and two thirds of that of the corresponding fluid and varies significantly with temperature and pressure.