Bimodal fan, heat exchanger and bypass air supercharging for piston or rotary driven turbine

A bimodal fan having a variable flow rate and thrust and power requirement without changing its pressure ratio, said bimodal fan comprising:

• a fan, driven by an Otto Cycle engine;
• a duct, enclosing the fan, for directing flow of air from the fan;
• and
• two concentric but separate flow paths within said duct said flow paths including:
• a first, inner flow path fully open all the time and sized to provide best take off performance with available horsepower, and;
• a second, outer flow path, concentric to the first, inner flow path, said second, outer flow path including a radial array of movable vanes for varying the flow through the second, outer flow path;
• and
• a low loss heat exchanger provided in at least one of the first and second flow paths, for transferring waste heat of the Otto cycle combustion engine from a least one of exhaust and cooling water, directly to fan discharge air down stream of the fan so as to remove the engine waste heat, and boost the fan system effective thermal efficiency by increasing the enthalpy of fan discharge air, the heat exchanger comprising a cluster of thin walled tubes which vary in cross sectional shape.

A bimodal fan having a variable flow rate and thrust and power requirement without changing its pressure ratio, said bimodal fan comprising:

• a fan, driven by an engine;
• a duct, enclosing the fan, for directing flow of air from the fan;
• and
• two concentric but separate flow paths within said duct, said flow paths including:
• a first, inner flow path fully open all the time and sized to provide best take of performance with available horsepower, and;
• a second, outer flow path, concentric to the first, inner flow path, said second, outer flow path including a radial array of movable vanes for varying the flow through the second, outer flow path;
• and
• a water injection system, coupled to said engine, for injecting water into an intake of said engine to reduce detonation and increase horsepower output of said engine, said water injection system comprising:
• a nozzle body, coupled to the intake of said engine, said nozzle body receiving pressurized air from the duct through the rear of the nozzle body and passing through an array of holes into a plenum chamber;
• a center bullet, provided within the nozzle, for providing a contour for a narrow nozzle annulus, said bullet being concentric to the nozzle body;
• a narrow annular gap, formed between the center bullet and nozzle body;
• an annular water chamber, formed in the nozzle body, for receiving pressurized water from a pressurized water source;
• and
• a circumferential gap leading from said annular water chamber to the nozzle annulus.

A method of generating variable thrust from a ducted fan without changing its pressure ratio, the method of generating variable thrust from a ducted fan comprising the steps of:

• generating, using a fan driven by an engine, a flow of air through a duct, enclosing the fan and directing flow of air from the fan,
• diverting the flow of air through two concentric but separate flow paths within the duct, the flow paths including a first, inner flow path fully open all the time and sized to provide best take off performance with available horsepower, and a second, outer flow path, concentric to the first, inner flow path, the second, outer flow path including a radial array of movable vanes for varying the flow through the second, outer flow path,
• directing the flow of air through a low loss heat exchanger provided in at least one of the first and second flow paths, and
• transferring waste heat of the engine from at least one of exhaust and cooling water directly to fan discharge air down stream of the fan so as to remove the engine waste heat, and boost the fan system effective thermal efficiency by increasing the enthalpy of fan discharge air.

A method of generating variable thrust from a ducted fan without changing its pressure ratio, the method of generating variable thrust from a ducted fan comprising the steps of:

• generating, using a fan driven by an engine, a flow of air through a duct, enclosing the fan and directing flow of air from the fan,
• diverting the flow of air through two concentric but separate flow paths within the duct, the flow paths including a first, inner flow path fully open all the time and sized to provide best take off performance with available horsepower, and a second, outer flow path, concentric to the first, inner flow path, the second, outer flow path including a radial array of movable vanes for varying the flow through the second, outer flow path,
• injecting water into an intake of the engine to reduce detonation and increase horsepower output of the engine, said step of injecting water into the engine comprising the steps of
• providing a nozzle body, coupled to the intake of the engine, the nozzle body receiving pressurized air from the duct through the rear of the nozzle body and passing through an array of holes into a plenum chamber,
• providing a center bullet within the nozzle, for providing a contour for a narrow nozzle annulus, the bullet being concentric to the nozzle body,
• providing a narrow annular gap between the center bullet and nozzle body,
• providing an annular water chamber, formed in the nozzle body, for receiving pressurized water from a pressurized water source, and
• providing a circumferential gap leading from an annular water chamber to the nozzle annulus.

A water injection system for injecting water into an intake of an engine to reduce detonation and increase horsepower output of said engine, said water injection system comprising:

• a nozzle body, coupled to the intake of said engine, said nozzle body receiving pressurized air through the rear of the nozzle body and passing through an array of holes into a plenum chamber;
• a center bullet, provided within the nozzle, for providing a contour for a narrow nozzle annulus, said bullet being concentric to the nozzle body;
• a narrow annular gap, formed between the center bullet and nozzle body;
• an annular water chamber, formed in the nozzle body, for receiving pressurized water from a pressurized water source;
• and
• a circumferential gap leading from an annular water chamber to the nozzle annulus.

A bimodal fan having a variable flow rate and thrust and power requirement without changing its pressure ratio, said bimodal fan comprising:

• a fan, driven by an engine;
• a duct, enclosing the fan, for directing flow of air from the fan;
• and
• two concentric but separate flow paths within said duct, said flow paths including:
• a first, inner flow path fully open all the time and sized to provide best take of performance with available horsepower, and;
• a second, outer flow path, concentric to the first, inner flow path, said second, outer flow path including a radial array of movable vanes mounted in the flow path before the fan, for varying the flow through the second, outer flow path.

A bimodal fan having a variable flow rate and thrust and power requirement without changing its pressure ratio, said bimodal fan comprising:

• a fan, driven by an engine, the fan comprising an inner first portion separated from an outer second portion, the first portion and second portion defining two concentric but separate flow paths;
• a duct, enclosing the fan, for directing flow of air to and from the fan, the duct including the two concentric but separate flow paths within said duct, the said flow paths including:
• a first, inner flow path duct portion fully open all the time and sized to provide best take off performance with available horsepower, the firs inner flow path duct portion ducting air to and from the inner first portion of the fan, and;
• a second, outer flow path duct portion, concentric to the first, inner flow path, said second, outer flow path duct portion including a radial array of movable vanes mounted in the flow path before the fan, for varying the flow through the second, outer flow path duct portion, the second flow path duct portion ducting air to and from the outer second portion of the fan.