Y-intake is synonymous with 'twin intake' or ' bifurcated intake'. These are referred to a pair of intakes in the wing root or on the two sides of a fuselage, feeding a single engine via a common plenum chamber. Y shaped intake is the popular choice for air intake in single engined fighter aircraft. The air intake must meet the engine mass flow demand over a range of aircraft speeds and altitudes with pressure recovery and low distortion of the exit flow. These types of intakes are normally side mounted and the two limbs of the duct are merged inside the fuselage into one and supply air at the compressor face with minimum turbulence and impact. The center line offset of the intakes with respect to the engine is a real challenge in designing the intake conforming to the constraints imposed by other aspects of the aircraft design. In the present work the flow and performance characteristics of a rectangular Y-intake diffusing duct studied extensively and the the experimental results are compared with numerical work after validate the numerical model and boundary parameters and observed that the pressure recovery increases with increase of aspect ratio and decrease in angle of turn.