Weirs are commonly employed for the purpose of measuring and controlling flow of water in open channels. Nonlinear weirs are considered to have better discharging capacities compared to linear weirs for same width of channel. Arched weir is one of the nonlinear weirs which has increased effective length compared to normal rectangular weir. The present study explores the hydraulic performance of arched weirs using FLOW-3D® software. Numerical simulations are carried out on arched weirs having central angles of 50°, 60°, 70°, 80°, and 90° whose convex side facing the upstream with corresponding weir heights of 0.18 m and 0.22 m. The variation of coefficient of discharge is examined for varying central angles and (H/P) ratio up to 0.45. Based on numerical results, the discharge coefficient of arched weir is determined and compared with expressions described in available literatures. The new models are proposed for coefficient of discharge for different weir angles using regression analysis. Arched weir with central angle 90° is observed to provide the maximum flow magnification of 1.32 to 1.18 over rectangular linear weir within the range of H/P values between 0.15 and 0.45. It is interpreted that an arched weir can prove to be effective practice to enhance the discharge capacity of weir.