Manifolds are designed to deliver fluid through multiple orifices of the manifold such that for a given inlet fluid pressure the fluid being output from the multiple orifices has a desired mass flow profile. The desired mass flow profile includes a desired mass flow rate and a desired direction and distribution of flow in three-dimensional space. The manifold is first modeled as a two-dimensional representation to determine manifold parameters necessary to achieve the desired mass flow profile within the two dimensions. Then, the manifold is modeled as a three-dimensional representation based on the parameters previously determined for the two-dimensional representation to determine manifold parameters of the third dimension that are necessary to achieve the desired mass flow profile within the three dimensions.