This paper presents the development of a novel omega-shaped resin transfer molding (RTM) tool, which is especially designed to host different types of sensors and to avoid common problems of RTM (e.g. uneven heating, low tool durability, deflection). Permeability measurements were executed in order to get real permeability measurements for numerical mold filling simulations. Three different kinds of flow behaviors (isotropic, orthotropic and anisotropic) were considered as filling patterns and the flow front predictions. Due to the U-shaped composite part design, the mold curvature effects on the flow front propagation caused by the increased fiber volume content in these areas were also taken into account. The tool was designed with a heating ability using purified liquid water guided to a channel circuit within both top and bottom halves of the tool. Deflection and heat transfer simulations were performed with the finite element method (FEM). All three executed simulations (filling, heat transfer and deflection) were used as a guideline for the final mold design.