Solidity factor of blade.
Blade solidity factor is the chord length divided by the blade spacing,
Blade spacing is the distance between two similar points on adjacent blades.
The blade having solidity factor less than one facilitates manufacture of the impeller in one piece using a molding process.
Solidity factor
The solidity factor is defined as the total blade area of the rotor divided by the swept area normal to the wind. Low solidity factor is highly desirable as a blade with low solidity factor will intercept a large area of wind with a small area of blade.
Turbines with high solidity usually suffer from a large degree of aerodynamic interference between the blades which results in low value of both tip speed ratio and power coefficient (The power coefficient tells you how efficiently a turbine converts the energy.)
Modular jet engines
Modern turbojet engines are modular in concept and design. The central power-producing core, common to all jet engines, is called the gas generator. To it are attached peripheral modules such as propeller reduction gear sets (turboprop/turbo shaft), bypass fans, and afterburners. The kind of peripheral fitted is dependent on the aircraft design application.
An example will be When GE collaborated in end of seventies and eighties with French Snecma on the CFM56 civilian engine build around a hot core of military F110, French had 50% of design work but worked on low pressure part and accessories and were forbidden to look on hot cores provided by GE (HP turbine and combustion chambers).
