FLUIDIC THRUST VECTORING

OUTLINE

• INTRODUCTION• VTOL / STOL• MECHANICAL THRUST VECTORING• FLUIDIC THRUST VECTORING(ADVANTAGE AND TYPES )

THRUST VECTORING FOR VTOL

THRUST VECTORING

MECHANICAL THRUST VECTORING

MECHANICAL THRUST VECTORING

FLUIDIC THRUST VECTORINGADVANTAGES

• Mechanical TVC involves deflecting the engine nozzle and changing the direction of primary jet.

• Fluidic TVC involves injecting fluid into or removing it from the boundary layer of primary jet to enable vectoring.

• Fluidic TVC system has the advantage of being light weight, simple, free from moving parts and reduced observability penalty.

FLUIDIC THRUST VECTORING

METHODS• Shock vector control method.• Coflow and Counterflow thrust vectoring.• Use of Synthetic jet actuator.• Fluidic throat skewing.• Dual throat thrust vectoring

SHOCK THRUST VECTOR CONTROL

Fluid is injected into ,the supersonic flow downstream of the throat at the divergent section.

Flow is robustly turned through oblique shocks in the nozzle.

Vectoring achieved at the expense of system thrust ratio.

COUNTER FLOW METHOD• Collars are placed on

either side of primary flow.

• Secondary counter flow is created between the collar and primary jet using vacuum.

• Resulting shear force between the flows, causes the primary jet to deflect and thus achieve thrust vectoring.

COFLOW METHOD• Uses Coanda effect and

momentum injection for thrust vectoring.

• Coanda surface,restricts the mass entrainment and flow tries to accelerate to balance momentum transfer.

• Pressure difference across the jet results, and jet is deflected closer to the surface, eventually attaching to it.

SYNTHETIC JET ACTUATOR• Oscillating diaphragm is

used to produce a controlled jet.

• Fluid is pushed out of the orifice, causing the formation of vortex sheet.

• Placed on either side of primary jet stream, with exit flow in the same direction of primary flow.

• TVC is achieved by varying the flow from the actuators.

FLUIDIC THROAT SKEWING

Primary jet can be skewed in a desired direction, by asymmetrically injecting the fluid at the throat, resulting in thrust vectoring. Symmetric fluid injection can be used to produce throttling effect

DUAL THROAT FLUIDIC THRUST VECTOR CONTROL• Two minimum areas, one

upstream and other downstream at nozzle exit, with a cavity between the two.

• Thrust vectoring is obtained by asymmetric fluid injection and by controlling separation and maximising pressure differential in the cavity.

• Study for varying cavity length and cavity convergence / divergence angle in progress.