Instructor comments: wow, excellent, keep it up. Make sure you start building something starting next Monday, May 8.
Ghana’s food production system relies heavily on sustenance farming. Farmers from Agbokpa, a Ghanaian village, source their water directly from a nearby lake using buckets. This method of irrigation requires extensive labor and multiple hours of work designated to purely the transportation of water.
To increase the productivity of Ghanaian farmers by providing them with resources to make more efficient use of their time and energy. To find a way to increase crop production to year round, in spite of the dry season.
Our goal is to make a modular water supply system that can convey water from nearby reservoirs to local gardens and small farms.
Limited information on what is needed by the Ghanaian people (Design constraints).
Speed of communication between us and our contacts.
Inability to actually be in Ghana and implement our project/ design our project in the intended space.
1. Research the needs of sustenance farmers in Ghana.
2. Design a modular, simple and inexpensive pumping system that can be.
3. Establish a working relationship with Burro Inc. and a village in Ghana.
1. Learn about solar and small scale pumps.
2. Understand the needs of subsistence farmers in Ghana.
DIVERGENT/CONVERGENT THOUGHT PROCESS:
Make a wheeled cart solar pumping station that can be moved from source to source as well as connected in series for higher pressure demands or parallel for higher flow demands.
Office Hours with Nathan Heston
We were encouraged to pick one part of the proposed system to focus on.
He was excited about the tank aspect of the design and recommended that we steer away from simply attaching a solar panel to a motor.
Nathan also mentioned the use of local supplies, available in Ghana, in the development of the future product.
Water Storage Tank
Modular Unit encompassing the the solar panel and motor
Develop a filtration aspect of the design
Experiment 1 : Brown Team’s Drippers
Using the design from the Brown Team for the drippers, we laser cut acrylic models and tested the flow of water through clear 3/16” vinyl tubing. We found that acrylic wasn’t the best material for the drippers and broke easily when the tubing was pushed through the opening. With an appropriate model size, with the opening tapering from 0.06” to 0.08”, we were able to test the flow of water. Unfortunately, while we did have a flow, the rate did not vary widely as the opening narrowed.
What we learned:
The flow rate depends on the water pressure, and pressure at which the water is entering the tubing. This rate will depend on the height of the storage tank, which affects how fast the water will come down.
Although cheap, acrylic is not the best building material for the drippers.
Initial communication has been made with the previous contacts. We have been in correspondence with Nate Heston , who advised us on the feasibility of our project and gave us insight on where previous classes and Brown left off. He advised us to narrow down to one part of the irrigation system and told us that he would provide support in whichever idea we decided to focus on. We were also put in contact with a variety of people who provided insight on the project before, including Clayton Carley (On the ground in Ghana) and Carol V. Brown (Ghana country Manager for Burro). We are currently in response with these advisors in attempt to develop a direction and gain more insight on the needs of the Ghanaian people.
Efforts in Shop
We’re still currently in the brainstorming stage of our project. That being said, we lack a concrete plan of action and therefore have not made any advancements in shop. However, we are developing ideas and making strides in the right direction.
EXPERIMENT 4: BRINGING EVERYTHING TOGETHER
The drip irrigation finally arrived after being shipped to us from Brown! The system included everything from the Tank, to the drippers. Our first day at the Student Experimental Farm, we set up the Brown system, cutting the pipes to match the size of our plot. We set up the system to fit 6 lines of crops. We were left with a lot of extra piping and drippers. The second day at SEF, we fit the drippers into the existing holes, plugged the ones that failed to line up with the crops, and made new holes with the hole puncher provided by the brown team. We then fed water into the system, straight from the hose, in order to check for leaks. On the 3rd visit, we tested our pump one last time with solar panels and then attached it the brown system. We were able to feed water from a bucket to the system using our pump. After a few minutes of waiting for the air to escape, water started to flow through our drippers. Success!
However, we did face some electrical challenges. We had difficulty with the creating a strong connection between our pump and panels. Our goal for the final presentation includes having a flawless demonstration of the system, without having the pump disconnect. Also, we hope for a sunny afternoon on the day of demonstration, as our problems with the pump started when the cloud coverage increased.
Graph 1: Predicting Percent Pump Efficiency from Pressure (PSI)
Interpretation of R^2:
Approximately 83.19% of the variability in Pump Efficiency percentage can be explained by the linear relationship with Pressure in PSI
Previous Work on Project with Burro:
Cal Poly Site: http://burrogravityirrigation.weebly.com/about.html
Brown Site: https://browndripirrigation.wordpress.com/
Elysa C. Briens: A second year EVNM student from San Diego, CA. I’m a big fan of green hills, the great outdoors, and travel. I aim for a future in outfield research, preferably pertaining to plant or soil science. While I don’t have too much experience with development yet, I am excited for the opportunities to come in my next couple years here at Cal Poly.
Lucas Salem: A fourth year BRAE student born and raised in Morgan Hill, CA. I am interested in urban farming, sustainable food production, energy and resource usage. I’ve had work experience in irrigation design testing, food processing operations, and harvesting equipment fabrication. I worked at the Irrigation Training and Research Center at Cal Poly and have seen first hand what a difference a good irrigation system can do for a farm. I hope to continue my engineering work in a career of resource management.
Simon Krauter: A fourth year ME student from Seattle, WA. I love to backpack, travel and be outdoors as much as possible. I’ve worked in the design and manufacturing fields primarily. I look forward to using my engineering experience to design solutions to make a difference in the world.
Caleb Ostgaard: A third year LAES student from Lake Forest, CA
Pictured (left to right):
Top – Simon, Caleb
Bottom – Lucas, Elysa