**3.1. Practical design criteria**

**Figure 2.** A large wind tunnel working section being lowered into place by a hydraulic arm.

62 Wind Tunnel Designs and Their Diverse Engineering Applications

developed, and reported boundary layer depths is presented in Table 1.

Although large portable wind tunnels requiring mechanical devices to install may be pow‐ erful and allow testing of relatively large surface areas, the logistics of transporting them and finding a suitable footprint of level ground to test limit their utility. Examples of medi‐ um-size tunnels that may be installed by human power include a German tunnel that was field calibrated [45], a portable boundary layer wind tunnel with a working section formed of three 2 m long elements that fits on a 5 m trailer [46], and another German design that incorporates a rainfall simulator to induce wind-driven rain splash [47]. A summary of port‐ able field wind tunnels, the dimensions of their working sections, maximum wind velocities

When Zingg published the design and operation of his first portable field wind tunnel [25], he offered seven practical criteria to consider. These practical criteria are listed below;


Another criterion that he used but did not list was the use of commercially available equip‐ ment when available.
