The past week was pretty good, too. This entry is a long one, so grab some popcorn.
We gave up on using a pump to deliver water to the evaporative cooling system, after some final failed attempts, and ordered the piezoelectric ultrasonic fogger. We also printed a silica cage to dry air before it enters the evaporative cooling segment, to keep humidity at a healthy level. We printed the bottle, cap and threads, after making some modifications to the bottle design and splitting the design to make it compatible for 3D printing. We also re-printed the fan blades with improvements, and finally assembled our long-awaited prototype 1.
We assembled prototype 1 and noticed the following modeling issues:
- Bottle cap diameter needs to account for 1% shrinkage
- Thickness between inner and outer diameters of caps is too thin for threads
- Since the screws are too short, which makes securing the DC motor difficult, we have decided to increase the number of holes from 2 to 4.
- We have decided to increase the diameter of the inner circle to be lofted for the top bottle cap. This is to make the cap lighter and save material.
- There is some extra space between the extruded bottle cap and outer bottle, which is still fine since this allows the wires for fan DC motor to pass through
We noticed that the air at the outlet deflects to the right, which follows what is expected of the circular airflow in a leaf blower. This agrees with the air trajectory predicted in simulations. We also measured the air velocity at the outlet to be 2.6 m/s, which agrees with simulations predicting 2.4 to 2.8 m/s. This was significant because it reassured us that any simulations we ran following this would be reliable and thus an efficient endeavour henceforth.
Once everything was printed and assembled, we first worked on testing the silica gel containers for proof of concept. The concept in question:
- If we remove more moisture from the air, will the temperature drop be higher?
- Sensible vs latent heat – Sensible heat in the air is converted to latent heat in the water droplets.
We tested the temperature drop experienced by air as it moves through and leaves the bottle both with and without our desiccators installed. Low and behold, the temperature drop was about 3 degrees celsius larger when the air was dried upon entering the bottle system by the dessicator.
Concept proven!
Meanwhile, Gabriel worked on the following:
- Discharge and recharge batteries and measure voltage
- Figure out how many components turn off with the accelerometer
Our next step: Designing silica cages and containers for the foggers. LET’S GO!