Table of Contents
Page OverviewThis page contains much of the information generated during the detailed design stage of MSD I. Topics such as engineering analysis, experimentation, prototyping, CAD models, assembly plans, a bill of materials, testing plan, a project budget, revised risk assessment, and a detailed design presentation can be found here. The table of contents to the right can be used to easily navigate to a topic on the page.
Prototyping, Engineering Analysis, SimulationThis section contains the prototyping, engineering analysis, and simulations associated with the detailed design of the water table. Some additional analysis performed in the systems design phase may not be found on this page and may be found in the systems design section.
ElectrolysisPreliminary test of electrolysis have been carried out to determine the feasibility of use for this application. The notes of the test are captured in the links below. The video clips were taken during the specified conditions.
Additionally, a pulsing circuit is going to be implemented into the electrolysis design. The initial thought is to pulse the power delivered to the electrodes which will allow the user to follow the flow more closely. A preliminary schematic along with the transient analysis for that schematic is shown below.
Students will be able to vary the pulse through the use of a potentiometer (variable resistor), this is not shown in the schematic below. The circuit was initially designed for an on/off cycle of ~10seconds (5seconds off / 5seconds on)
The ASME water table was investigated as a possibility for testing electrolysis through moving water. Because of massive leaks encounterd, this approach was abandoned. Testing was performed on 1/18/13.
The RIT MET Department let us experiment with flow visualization in their water channel. It is operated through the use of a valve to control pump flow, a sluice gate at the inlet, and another gate at the outlet. Steady state conditions were not easy to reach but several tests were conducted at estimated flow rates of 6.8in/s and 3.4in/s. This testing was performed on 1/23/13.
Pictures from test setup:
Videos showing streamlines over a plate:
Tank Construction AnalysisThe feasibility of bulding a tank for the water table was investigated by constructing a small scale tank. The process used in doing so is documented in the link below. After the investigation of building a tank the P13465 team has determined that it is possible to build the tank, however, due to the challenges associated with it, it has been determined that it should be order instead.
PumpThe following spreadsheet shows the calculations to find the power requirements for the pump to overcome gravity in the system at the desired flow rate. The calculations also take into account head loss, assuming 120in of piping (an overestimation). The pressure required to overcome the gravity and also head loss is shown in a combined chart on the bottom. Because pump efficiencies are assumed to be less than 100%, the efficiency of the 1 horsepower pump was taken into account. As long as pump efficiency is greater than 40% (assumed), the pump will have enough horsepower to overcome the flow rate.
On the pump selection tab, the pump's datasheet is saved.
Drain CalculationsIn order to assure that the drains were sized appropriately, the estimated flow rate without any pump section was calculated. The estimated flow rate out of the channel of the drains was estimated to be more than the estimated flow needed through the channel. In the actual configuration, the pumps will control the flow rate through the drains, but the drains are big enough for these flow rates.
Test Channel Magnet CalculationsMaking some assumptions on coefficient of friction, it was possible to find the pull forces required to keep the test channel sections secure. The first set of calculations used the dynamic pressure to find the forces, divided the force by 4 magnets, and found a pull force per magnet of 2.4 lbf (very doable). Nozzle forces from the contraction section were calculated to be very small at 0.25lbf. The magnets will hold those forces. The other case assumes there is 3" of water on one side of the wall and no water on the other side, thus represents an extreme case.
Test SpecimenHelicoil configurations and magnetic holders were analyzed. The magnets to use would need to be extremely strong to meet the test specs or force on the test specimen, but they are achievable.
Water Supply CalculationsCalculations were performed to make ensure that the water reservoir would have enough water to fill the system and drain properly. The following link shows the feasibility analysis performed.
Reynolds + Froude Number Flow AnalysisThe following link contains tables which identify flow rate and Reynolds Number analysis' for different flow speeds, flow depths, and test specimen sizes. This was developed as a reference sheet for the table operation. The ranges extended beyond the the allotted limits of the table to examine if the table were built on a larger scale and/or if flow were sped up, what Reynolds numbers could be obtained.
The Froude Number for open channel flow was also calculated. This is the ratio between the channel velocity and the wave speed of the free surface. If Fr>1, a supersonic flow analogy for the flow can be used. The flow table is not designed to do this.
Cart Strength AnalysisThe cart was analyzed for loading with 55 gallons of water (neglected weight of other items as they are dispersed throughout the setup. The factor of safety found analytically was found to be 2.8 and the factor of safety found using ANSYS was found to be over 4. The added strength of the cross beam which tied the boards together likely helped with the strength. The paper below documents what was done.
Drawings, Schematics, Flow Charts, Simulations
CAD ModelsCAD models were completed for all systems of the project. The models demonstrate the interactions between systems, including the water table, pump, water tank, and cart structures. Piping was modeled between all system components. The model includes all major components, which are shown in the Bill of Materials. All CAD files may be accessed on EDGE.
CAD Drawings & SchematicsCAD drawings were completed for components that were to be manufactured/machined by the MSD Team. The CAD drawings can viewed by clicking the links seen below.
Assembly ProceduresThis section contains detailed documents outlining the procedure for manufacturing components of the water table project.
Disassembly ProcedureInstructions outlining the procedure for disassembling the system is captured in the link below.
Bill of Material (BOM)
The intended budget/BOM for the P13465 water table is denoted in the link below.
The budget may also be downloaded as an excel file:
Test PlansThe test plan outlines the process which the team will utilize to justify that the final design meets the engineering specifications. The testing plan addresses what will be tested, how it will be tested, who is responsible for determining if the specification is met, and possible risks and contingencies. The testing plan uses a pass/fail criteria for each engineering specification. The document outlining the procedure for the P13465 water table MSD can be accessed by the following link:
A risk assessment of the project was developed to plan for a variety of possible risk items that may occur during the project. This allows the team to be prepared for possible problems the project may have in the future and to think about how the team will work through it in advanced. In the link below a variety of risk items are categorized with corresponding importance and actions to minimize risk as well as who is responsible for each risk. This risk assessment is an update to that given in the Systems Design section based on the progression of the project as of 2/8/13.