CFD is taken notice as a cost effective design tool for aircraft components. UPACS is a convenient CFD platform, since it supports a large degree of versatility using various kinds of solvers. However, its major drawback is a long simulation time. We have developed a UPACS accelerator named FLOPS-2D with multiple FPGA boards, and implemented some core functions. Here, by using flexibility of FPGAs, the selectable functions are proposed. All possible flux limiter functions in MUSCLs are implemented independently, and only required functions are selected and implemented with other modules to form the optimal structure. All implemented functions achieved at least 24 times higher performance than that with the Core 2 Duo, and configurable solvers using a desired flux limiter function and the number of arithmetic pipelines are developed.