Can the L-1 design be configured as an indoor Vertical Wind Tunnel ?
Absolutely. The L-1 vertical wind tunnel can be configured with an outdoor or indoor flight area, with or without a tube.
What are the advantages and disadvantages of an indoor vs. an outdoor flight area ?
An outdoor configuration is more aesthetically pleasing for fliers, spectators and photography. It is less expensive.
An outdoor VWT is affected by weather and wind. Noise escapes outward. Sunlight and weather age the net and/or cushions more quickly.
An indoor configuration is shielded from weather and wind.
An indoor configuration without a tube contains the noise and so is not as quiet for the spectators. The enclosing structure adds to construction costs.
What are the advantages and disadvantages of a tube enclosing the flight area ?
An outdoor configuration with a tube is not affected by wind or weather. It is not affected by atmospheric mixing. This means the jet does not expand and therefore maintains the maximum
airspeed, without wind induced turbulence. Noise does not escape and so spectators experience a very quiet environment. Most of the noise escapes upward. This is an advantage where the flight area passes through a
restaurant for example. Fliers can not fall out of the jet. Fliers can walk up the walls of the tube.
A flier can crash into a tube, possibly causing injury. A flier who falls against the tube might slide down to the net head first. If the door is not flush a flier can fall into the
doorway possible causing injury. It is difficult to provide a soft net in the smaller diameter of a tube. These things tend to inhibiting the flier from learning extreme maneuvers. The entrance to a tube must be
kept closed while the machine is operating. The door must be very strong. Fliers cannot come and go from the flight area during operation. Flier contact with a transparent tube will scratch it requiring frequent
polishing or resurfacing. A tube must be very structurally sound and adds to the construction cost. It may be necessary to use Lexan (polycarbonate) in a tube. Lexan is very expensive, curved lexan is even
more expensive. It is more difficult to see fliers in a tube. Fliers feel more confined. Fliers are more restricted, in an outdoor configuration, a fliers hands or feet can pass outside the jet. This makes the jet
seem wider. Due to jet expansion, the flight area of a jet without a tube is wider. It is more difficult to light the inside of a tube. External light causes reflections and glare that reduce visibility.