This question sets forth a project of considerable undertaking. Nevertheless, a relatively small wind tunnel is feasible, particularly for low-speed work (i.e. low Reynolds number), if there is willingness to use care and understand the technical issues in smoothing airflow and eliminating turbulence in the free stream flowing through the model test section (about 1/16th the area or even smaller, compared to the test section pictured in the question). This link here will show the similarities between a large engineering wind tunnel, and a much smaller version used at the same facility. The smaller version has been ideal for low-speed work, and has been used advantageously in that realm. A description of the main facility for the associated large, engineering wind tunnel is found here. In the United States, much work has been done with intermediate sized wind tunnels capable of reproducing results of equivalent quality to those obtained in the large wind tunnel mentioned herein. These wind tunnels are located at a) Princeton University, b) University of Illinois Urbana Campus, and c) Notre Dame University. These wind tunnels, although relatively small, are quite substantial. The wind tunnel used at the University of Illinois Urbana has produced engineering results of the highest quality in the study of airfoils, and in comparison of those results with computational methods available from various sources.