Initial Phase
Initial proposed design of prototype
The initial proposed design of the prototype involves the use of a mist generator, glass containment and a high intensity light source. However, we realized that the water droplets formed from the mist generator was too fine to form rainbows. In addition to that, mists of water going to the glass containment might coalesce to form a layer of water droplets on the surface of the glass containment, preventing the formation of a rainbow.
Second proposed design of prototype
The second proposed prototype involves the use of a sprinkler, an air curtain and a water reservoir. The mist maker which was originally proposed was substituted for a sprinkler unit. The water droplets formed from the sprinkler are large enough for the formation of rainbows. The initial glass containment is substituted for an air curtain as it prevents the coalescence of water on any surface. In addition, it minimises water wastage as most of the water from the sprinkler would be directed in to the water reservoir. However, as advised by Dr. Ho, we were told to concentrate on forming the rainbow in a closed, table-top environment first, and that the water containment and air curtain can be focused on later.
Third proposed design of prototype
The third proposed design only involves the use of a light source, water sprinkler and a box made out of acrylic. Its as simple as that.
Fourth proposed design of prototype
The fourth proposed design is for the room-scale version of the rainbow. This prototype involves a spotlight, water pump and a black backdrop
Prototype
Prototype 1
Prototype 1 was made with clear acrylic. Black tape was used to ensure that the background where the torchlight is shining at is dark. However, the background was too reflective and it drowned out the rainbow.
Formation of double rainbow in second prototype
Another prototype was then constructed. The dimensions of the second prototype was a slightly scaled-up version of the first prototype. However, the box was made with black acrylic which was coated with matte paint. As a result, we were able to observe the formation of a rainbow in the second prototype. After preliminary testings, we designed a room-scaled prototype.
Final Product
Set-up of final product.
The Final product is set-up in the same manner as the 4th proposed prototype design. We used 2 different kinds of light sources. A LED spotlight and a HMI (Hydrargyrum medium-arc iodide) spotlight.
Final Product images/videos with descriptions.