It's not a brand, but a concept. It stands for "Variable-Cycle-Engine". In fact, they are designed to operate in one mode at subsonic speeds and another at supersonic speeds.

-This possibility of configuring the engine according to its intended use has been attempted by major manufacturers.

-In fact, it's a combination of a classic subsonic engine and one specifically designed for supersonic speeds.

"VCE engine with both possibilities"

"VCE engine with both possibilities"

-General Electric's solution is shown below; the top half of the next section shows it in supersonic mode and the bottom half shows it in subsonic mode.

-These are engines that were considered for future SSTs in the 1980s.

“Cross-section combining both modes”

-GE's proposal differs from that of P&W, and even from the Japanese NEDO; below we show the Rolls-Royce proposal.

“Rolls-Royce's solution, in supersonic mode"

-And also the Snecma formula.

“Snecma solution, in subsonic mode”

-Regarding Snecma and Rolls-Royce, the solution adopted for the Concorde differs in form, though not in principle.