Beam dumps are essential components of any accelerator system. They are usually located at the end of the beam delivery systems and are designed to safely absorb and dissipate the particle energy. In the second stage of the proposed International Linear Collider (ILC), the electron and positron beams are accelerated to 500GeV each (1TeVtotal). Each bunch will have2Χ10¹⁰  electrons/positrons, and 2820 bunches form one beam bunch train with time duration of 0.95 ms and 4Hz frequency. The average beam power will be 18MW with a peak power of 4.5GW. The FLUKA code was used to determine the power deposited by the beam at all critical locations. This data forms the input into the thermal hydraulic analysis CFD code for detailed flow and thermal evaluation. Both 2D and 3D flow analyses were carried out at all the critical regions to arrive at optimum geometry and flow parameters of the beam dump. The generation and propagation of pressure waves due to rapid deposition of heath as also been analyzed.