156B Week 4

Overview of Status of Analysis, Design, Fabrication, Tests, etc.

• After consulting with Tom, a method was devised to measure the pressure at the outlet of the pump and accumulator by measuring the pressure of the water pushing against a gas pressure gauge with its outlet nozzle closed.

  • The pump and the combination of the pump with the accumulator were tested with this method

  • measurements have been made and the pressures at the outlet of both the pump and accumulator have been determined to be the same, as in at 80 psi (551 kPa) pump pressure the accumulator produced around the same pressure at its outlet.

• Prototype design has been revised to include a 6 in (15.2 cm) diameter cylindrical tank at one side of the misting system container, while the pump and accumulator will be on the other side

  • Acrylic will be used to support the mister fans onto the container unit

  • notched aluminium beams will be used to adjust the length of the mounts

  • mounting to the cart is still to be determined

Accomplishments from Previous Week

• Mistcooling brand mister nozzles were determined to produce too narrow of a misting cone (less than 20 degrees) at 80 to 90 psi (551 kPa to 620 kPa)

• Hago brand steel misters provided the widest and longest reaching mist (about 80 degrees and 20 cm)

• Components for the housing, water tank, and bar supports have been acquired, while smaller components, like capacitors, are being ordered. 

Goals for Next Week (list names after each item). Use specific and measurable objectives.

• Build the plate for pump/accumulator/converter (Chota and Cristobal)

• Design and build the adjustable mounting system (Oscar and Erasmo)

• Design and build gooseneck/fan combination (Chota and Cristobal)

• Have a system that is ready to be put on the cart (adjustable and mountable without drilling into the golf cart bars)

Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)

• The in-market mister systems that run off of a single 8 V battery instead of using the 24 V to 12 V converter have a step-down current limiter leading into the pumps (4-15-17)

  • The final design will use these thermoresistive current limiters in conjunction with capacitor filtering, as per Steve Robert's recommendation (in person meeting 4-21-17)

    • These current limiters and capacitors can be relatively inexpensive when purchased in bulk (about $0.40-$1 and $3-$5 each, respectively)

Instructor Comments from Last Meeting and Actions Taken to Address these Comments  (indicate date of comments and if via email or in person)

• 24 V fans are common and inexpensive and can run off of two 12 V batteries or three 8 V ones

• Additionally, step down regulators can be easily implemented to the fans to prevent them from running at variable speeds (in lab meeting 4-17-17)

  • possible replacement fans should be considered, but for now lowering manufacturing and assembly costs are the main focus for the system 

  • step down limiters have already been implemented by our sponsor and seem to be working well on the courses

• Corrosion in the mister heads is likely due to the nozzle housing being made of a different metal to the nozzles themselves (4-17-17)

  • Many common nozzles are made of stainless steel or brass with nickel plating, while the housing is aluminium, as such the team has already chosen the steel nozzle and will have to make a new housing for it.

• Automotive supply shops may have useful components for the team to us, such as spring loaded clamps and car hoses (4-17-17)

  • For testing purposes, the team has utilized spare hosing and screw clamps from the machine shop with Tom's permission 

Comments from Other Students in the Class (indicate date of comments and if via email or in person)

• Tom and Ian assisted in threading a large metallic part for another team and should be consulted for the nozzle housing (4-18-17 at machine shop)

Risks and Areas of Concern

• One of the capacitors used in testing has a broken connection, and new 10,000 uF capacitors are being ordered

  • Ian has offered a lower capacitance model, but the filtering may be less than ideal to the 15,000 uF one desired

Resources or Information Required but not Available

Schedule

• The next major milestone is to have the entire setup be built and ready to put on a cart

Budget (list amount spent and amount remaining)

• Budget Limit: $1,800.00 

• Total Spent: $123.57 

• Remaining: $1,676.43

Progress on Report and Webpage

• Finished Impact on Society on Report