The main function of a scramjet inlet is to capture air flow from the incoming hypersonic stream, compress it through a series of shocks or compression waves, and provide uniform flow to the combustor. There should be maximum mass capture along with a minimum stagnation pressure loss in the inlet. The shock waves in the inlet duct interact with the boundary layer on the walls and can result in flow separation due to strong adverse pressure gradient across the shock wave. The shock/boundary-layer interaction often results in a complex flow pattern, comprising of additional shocks, expansion waves, shear layer and separation bubble. The separation bubbles are highly viscous, and hence increase the stagnation pressure loss. Peak values of pressure, skin friction and heat transfer rates are found at reattachment point. Also, the separation bubble acts as a blockage to the flow inside the inlet duct and can result in inlet unstart. It is therefore important to predict the shock/boundary-layer interactions in a scramjet inlet, including the size of the recirculation region, accurately. Reynolds-averaged Navier-Stokes methods are commonly used in simulation of practical configurations of engineering interest. However, their accuracy is often limited in shock dominated flows, where conventional turbulencemodels developed for low-speed flows do not predict the underlying physics correctly. Several modifications have been proposed in literature [1], namely, compressibility correction, realizability constraint, rapid-distortion correction and length-scale correction. Theirperformance vary from one test case to another. The flowfield in a shock/boundary-layer interaction is inherently unsteady. Sinha et al. [2] found that unsteady shock interaction with incoming turbulence fluctuations dampens the amplification of turbulent kinetic energy. A correction was added to standard one- and two-equation turbulence models to account for this damping effect. The resulting model predictions were found to match DNS data of turbulent kinetic energy amplification across a shock. The shock unsteadiness modification when applied to canonical compression corner [3] and oblique shock impingement flows [4] improved the prediction of flow separation point, and the resulting pressure and skin friction distribution. In a practical inlet configuration, presence of geometric variations add to the overall complexity of the flowfield. In the absence of experimental data, CFD is often relied upon to predict and improve the performance of scramjet inlets. It is therefore essential to perform detailed CFD simulations of the flowfield inside an inlet duct. The focus of the current work is to study the reflection of the cowl shock and to predict the resulting separation bubble size accurately using the shock-unsteadiness model.