PROVISION OF A SPLITTER IN DUAL AIR INTAKE SYTEM PLENUM CHAMBEROF A TURBO-SHAFT ENGINE FORSYMMETRICAL FEEDING
Background of the Invention
Helicopter power plant consists of an Intake, Plenum Chamber, Compressor, Combustion, Turbine and the Exhaust systems. In general notation Intake (Figure 1) is responsible to supply the flow to plenum chamber and plenum chamber feeds the flow to the compressor.
A pair of intakes feeding the air (Figure 2) to a single engine via a plenum chamber is referred as the twin intake system. The helicopters withrsingle engine are'provided with the"dual intake system. The two intake ducts on either side are to facilitate the symmetrical flow feeding to the engine (compressor). Usually the intake ducts are very short in length as space and weight are constraints. Within this short and small space the air must bend orthogonally twice before reaching the compressor. As a result massive separation takes place in the duct and the same may be ingested into the compressor.
The two flows with high turbulence levels may not be identical (symmetrical) though the geometry is symmetrical. The flows with the massive separation are obvious to have asymmetrical nature from the left and right intakes. On the other hand the flows from two intakes collide in the vicinity of compressor inlet. Over all the design of dual intake system is more challenging and complex process.
One of the major and obvious problems of dual intake system for a single engine is flow asymmetry. Further this may result in excess of the pressure loss, distortion and the swirl. Primarily the intake system performance is accounted through the pressure loss, flow distortion and the flow swirl.
Pressure loss affects the required power to be produced by the engine. In^addition, the turbine gas temperatures will also rely on the pressure loss for the required power levels. This affects the thermal life of the power turbine blades.

Summary of the Invention
Distortion mainly affects the compressor performance and the loading characteristics. Uneven loading of compressor blades either circumferential or radial directions occurs as a result of the non-uniform flow. The consequences could be the vibration and the effect on fatigue life of the blades along with the compressor surge.
Swirl affects performance of the compressor by means compressor surge. Surging is analogous
to stalling of a lifting wing. Surging occur due to the altered inlet velocity angles of the
( compressor blades.
Altogether, they influence the engine performance and the engine life to a great extent. In order to address this issue a study was conducted at HAL in RWRDC. Amongst many schemes, a scheme with a splitter placed vertically at the plane of symmetry of the plenum to avoid the interaction of left and right incoming flows has shown significant improvement. The splitter plate inclusion was working to a great extent to enforce the symmetrical feeding of the flow to the compressor. The effect of splitter is further improving the intake performance in terms of the Pressure Loss, DC60 and Swirl.
The splitter is located in the plenum as shown in Figure 3. The flow patterns observed without and with proposed plenum splitter can be seen in Figure 4 and Figure 5.
The claims I made are here under
1.A splitter is a device that placed at the midst of a engine plenum chamber of a twin intake system to prevent the interaction of the right and left incoming flows.
2.A splitter as said in claim 1, using as a complete or partially of the plenum chamber.
3.A splitter as said in claim 1, using to enforce the symmetrica) flow pattern.
4.A splitter as said in claim 1, using to eliminate the mass imbalance between left and right intake ducts.
5.A splitter as said in claim 1, using to avoid the imbalance in forces and moments towards the stability improvement of the helicopter.
6.A splitter as said in claim 1, using to reduce the pressure loss or to increase the pressure recovery at compressor inlet.
7. A splitter as said in claim 1, using to reduce the flow distortion at compressor inlet plane.
8.A splitter as said in claim 1, using to reduce the flow swirl at compressor inlet plane.
9.A splitter as said in claim 1, using to improve the compressor surge characteristics.
10.A splitter as said in claim 1, using for the purpose mentioned in claims 6,1, 8 and 9 either together or for individual benefit.
11.A splitter as said in claim 1, using to reduce the flow turbulence and the noise induced by . the turbulence in intake.