Patent ID: 7530217

Claim:
An axial flow positive displacement engine comprising: an inlet axially spaced apart and upstream from an outlet, a core assembly including an inner body disposed within an outer body and the inner and outer bodies extending from the inlet to the outlet, the inner and outer bodies having offset inner and outer axes respectively, at least one of the inner and outer bodies being rotatable about a corresponding one of the inner and outer axes, the inner and outer bodies having intermeshed inner and outer helical blades wound about the inner and outer axes respectively, the inner and outer helical blades extending radially outwardly and inwardly respectively, the inner helical blades extending radially outwardly from an inner hub of the inner body, the core assembly having first, second, and third sections in serial downstream flow relationship extending between the inlet and the outlet, the inner and outer helical blades having first, second, and third twist slopes in the first, second, and third sections respectively, the first twist slopes being less than the second twist slopes and the third twist slopes being less than the second twist slopes, and a combustion section extending axially downstream from the second section through at least a portion of the third section.