Combustion Instability Research Facility

Combustion Instability Research Facility

F1: Combustion Instability Research Facility


Combustion Instability Research Facility


The screech combustion instability is one of the most detrimental and, in fact, a fatal issue in the development of a high-performance afterburner. Essentially, screech combustion instabilities are high-frequency transverse periodic oscillations driven by combustion and which are then manifested as large amplitude oscillations in the afterburner duct pressures accompanied by the characteristic high-pitched audible tone. These screech instabilities can cause rapid failure of the afterburner chamber due to large fluctuating pressure rises, enhanced wall heat transfer and large amplitude structural interactions. 

This versatile test facility that was established recently under a programme sponsored by Gas Turbine Research Establishment (GTRE) under the Gas Turbine Enabling Technology (GATET) initiative has the capability to simulate inlet conditions of a typical turbofan afterburner in a scaled test module.  Studies on the attenuation of screech combustion instability essentially by using passive methods is being carried out in this test facility.


F2: Fluidic Thrust Vectoring Test Facility



High-performance, highly maneuverable combat aircraft employ mechanical thrust vectoring nozzles.  Although these nozzles are very effective, they have many disadvantages like weight, complexity, sluggishness and the crucial high IR signature Hence, there have been serious efforts to develop light weight, fixed-geometry, nozzles which use fluidic thrust vectoring for unmanned, stealth combat air vehicles.  A novel technique of virtual aerodynamic nozzle internal surface shaping along with the incorporation of a yaw-plane aligned flow-splitting perforated strut within the nozzle has been developed in this test facility to achieve controlled fluidic pitch deflection of the exhaust jet.


F3: Pulsejet engine test facility

In the field of experimental research, engineers and scientists have used flow visualisation techniques to understand the fluid dynamics of complex phenomena by non-intrusive methods.  It helps to understand the physics of the flow in an effective manner. In a pulsejet engine, which is a variant of the conventional ramjet engine, combustion occurs in pulses and the propulsive force is due to an intermittent exhaust jet; a reaction to the rearward flow of hot gases.  A unique, twin-beam shadowgraph technique and high-speed imaging technique using chemical tracers have been developed for visualizing the unsteady combusting flow phenomena in a hydrogen-fuelled valveless pulsejet engine.  These techniques have been shown to be a powerful tool to understand the flow phenomena in an unsteady combustion system, and thereby help in the  design of such engines



High-speed imaging of hydrogen Flame structure in a transparent quartz glass valveless pulsejet engine


F4: Monopropellant Micro-thruster laboratory



 A test facility for conducting developmental studies typically on a 10 N class hydroxyl ammonium nitrate (HAN) based microthruster has been set-up. It uses a blend of Hydroxyl Ammonium Nitrate (HAN), as a green replacement for the currently used monopropellant hydrazine, which has a major disadvantage of in being toxic.   In addition, a vacuum test facility has been specially set-up to study the performance at low Reynolds numbers of both rectangular and 2D axi-symmetric nozzles for this class of micro-thrusters.  Studies using CFD coupled with the NASA CEA programme of various HAN monopropellant blends to evaluate the performance in terms of specific impulse, density specific impulse and adiabatic flame temperature have been extensively used in this programme.  





C Rajashekar

Joint Head, Propulsion Division

F1, F2, F3, F4



F1, F4

H S Raghu Kumar

Technical Assistant

F1, F2, F3, F4

Fakruddin Agadi


F1, F2 ,F4


F1: Combustion Instabilities Research Facility (CIRF)

F2: Fluidic Thrust Vectoring Test Facility (FTV)

F3: Pulsejet Engine Test facility

F4: Monopropellant Micro-Thruster laboratory

Last updated on : 22-03-2019 11:11:07am