More than 30 years of careful comparative analysis confirms that QUASITURBINE is an optimal engine concept, perfecting both Piston and Wankel without their specific constraints (with substantial efficiency, environmental and mechanical advantages), while the old intuitive concepts hardly provide new solutions to modern challenges (despite major peripheral improvements?). In brief, let us mention some of the concept comparisons explained in detail in: https://www.ijsr.net/archive/v14i2/SR25210033851.pdf

First, the fundamental obstacles of Piston and Wankel (P-W) arise from the alternation of axial or radial (in Wankel) chamber volume, which requires the use of a central eccentric crankshaft, a large and heavy device to convert pressure into rotary motion. / The QT concept uses only a non-intuitive tangential variation of the chamber volume, requiring no central engine shaft at all to function properly (but can accept and drive any straight shaft if suitable in application);

Second, alternating axial or radial chamber volume requires volume reset on return, which prevents continuous positive engine torque (interrupted by cycle dead time, 75% for the 4-stroke piston and 25% for the Wankel). / On the periphery of the QT, the blade (similar to the piston surface) continually passes from one chamber to the other, allowing continuous cycling and uninterrupted positive torque;

Third, alternating P-W chamber volume variation imposes on a P-W chamber walls a zero axial or radial velocity at the top and bottom (disrupting the homokinetic fluid flow). / In the QT, the moving chamber wall keeps rotating, accompanying the fluid flow from a maximum rotational speed where pressure builds up TDC, to a minimum rotational speed at the BDC maximum chamber volume. In the QT, ignition never occurs on a chamber wall at rest as is always the case in the P-W, a condition favorable to detonation with the QT-AC model;

Fourth, the P-W alternation produces a symmetrical volume variation (without differentiation between intake and exhaust) and a unique pressure-time profile imposed by the rotor geometry, but generally incompatible with modern combustion and fuel optimizations. / In the QT, the rotor being deformable, it does not impose a unique stator confinement shape, unlike the Wankel. The QT rotor confinement profile (and chamber pressure time variation) can even be asymmetrical and shaped by several degrees of freedom parameters independent of the rotor.

As the Wankel is in fact a 3-piston oblique radial engine, it has little in common with the Quasiturbine tangential pressure torque converter, which has attracted considerable attention due to its different properties from both the Piston and the Wankel, and explaining why several conceptual difficulties of the Wankel engine remain unresolved. The Quasiturbine highlights the great potential of rotary engine concepts for future engines and applications, particularly with synthetic and hydrogen fast-burning fuels, while contributing to the realization of clean and efficient HCCI and a photo-detonation mode.

Simplicity is the ultimate sophistication - Da Vinci
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