Flood

This research endeavor, conducted by Dr. John LaRocco, Dr. Qudsia Tahmina, and John Simonis at The Ohio State University, is dedicated to the development of an Elastocaloric atmospheric water harvester. Specifically, the primary objective of this project is to construct a system that can be juxtaposed with a conventional desiccant wheel system for the purpose of energy efficient water harvesting. Included in this repository is the evaluation of the efficiency and effectiveness of the newly developed system in comparison to its traditional counterpart. This project is a significant and novel step towards innovative solutions in the field of water harvesting technology.

Requirements

Software

• VSCode
• Platform IO
• Git
• Arduino IDE
• PySR
• PrusaSlicer or other slicer

Hardware

• FLOOD-BOM
• 3D-Printer
• Screw Driver

Table of contents

• Models & Construction
• Data
• Datalogger
• Testing
• Flood Equations
• Flood MCU
• Flood Photos
• License

Models & Construction

For this project, all pertinent 3D models are housed in the FLOOD-3DF directory. This directory is organized into the following sub-directories for ease of navigation and access:

1. Proto: This contains both STEP and STL files of the final prototype.
2. Control: This includes the STEP and STL files for the Control Harvester.
3. Deprecated: This houses the STL files of designs that are no longer in use.

Details

Control Water Harvester Assembly Overview and Instructions

The Control Water Harvester utilizes a desiccant wheel design, leveraging a heat lamp to dry out pockets of desiccant and a fan to circulate heated air through the silica gel desiccant. The assembly process is as follows:

1. File Download: Retrieve the STL files from FLOOD-3DF and the .3MF file if you plan to print the design on a standard Ender 3 PRO.
2. Setup: Import the model or .3MF into an FDM 3D-Printer slicer such as PrusaSlicer and select a material profile for PETG, which is necessary for higher temperatures.
3. Slicing: Configure a print with one wheel base and eight wheel rungs. Ensure the slicing settings include 100% infill, supports everywhere, and a layer height of 0.16mm or lower. Refer to the .3MF file for printing orientations
4. Assembly: Connect each of the rungs to the wheel base and secure each with M5 bolts and nuts, as specified in the Bill of Materials (BOM).
5. Testing: Upon completion of assembly, conduct a test using a lab power supply. Ensure the availability of fans and a heating device.

NiTi Prototype Assembly Instructions

The NiTi prototype employs a straightforward gantry system, powered by a high torque stepper motor. A T8 leadscrew is incorporated for a simple mechanical advantage to apply stress to the NiTi wires. The assembly process is as follows:

1. File Download: Retrieve the STL files from FLOOD-3DF and the .3MF file if you plan to print the design on a standard Ender 3 PRO.
2. Setup: Import the model or .3MF into an FDM 3D-Printer slicer such as PrusaSlicer. Select a material profile for PETG, which is necessary for higher temperatures.
3. Slicing: Configure a print with one of each part, except for the anchors, of which you should print two. Ensure the slicing settings include 100% infill, supports everywhere, and a layer height of 0.16mm or lower. Refer to the .3MF file for printing orientations
4. Nut Selection: Based on the dimensions of most of the nut pockets, identify suitable metric nuts.
5. Assembly: Secure each of the items in accordance with the provided render.
6. Gantry Fastening: Ensure the use of the appropriate metric T-nuts for fastening to the supplied gantry.
7. Testing: Upon completion of the mechanical assembly, refer to the wiring diagram provided below and prepare for testing. You will need to either develop your own code for controlling the motors or utilize the open-source GRBL firmware.

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Wiring

Control Water Harvester

The control water harvester uses one PC fan and a generic ~150-watt heat lamp. It is mounted to a piece of wood and turns with heated air blowing through each rung filled with desiccant on the wheel. For an example setup please see FLOOD-Photos. Water recorded was done using the sensor setup found in FLOOD-Schematics.

NiTi Water Harvester

The NiTi water harvester uses a generic 8-amp DC barrel jack power supply. It can be mounted to a piece of wood and during testing was controlled with an Atmega328p microcontroller running the GRBL firmware. For an example setup please see FLOOD-Photos. Water recorded was done using the sensor setup found in FLOOD-Schematics.

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Data

Currently, all data for this project can be found within the FLOOD-Data folder. This folder currently contains:

• Control (XLSX)
• Prototype (XLSX)
• Analysis (Jupyter Notebook)

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Datalogger

This project currently uses a compiled Datalogger from a previous research project from this team. Currently, this binary is only compiled for Windows systems and is present within the FLOOD-Datalogger folder.

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Testing

Project Testing Procedure

The testing procedure for this project was executed with a straightforward approach. The following steps were undertaken:

• Assemblies: Both the prototype and control assemblies were positioned within an enclosure equipped with a continuously operating humidifier.
• Data Gathering: Data was systematically collected at regular intervals of 10 seconds. Measurements, such as current, were averaged over this time frame.
• Noise Reduction: The averaging of measurements over the specified time frame was implemented to effectively mitigate the impact of noise and potential outliers.
• Execution: A total of three tests were conducted for both the control and the prototype assemblies.
• Duration: The entire testing procedure was carried out over a cumulative duration of 30 minutes.
• Water Sensor: The resistive water sensor was calibrated using a control amount of water for precision before any water was harvested. This methodical approach ensured a comprehensive evaluation of the project components under the specified conditions.

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Flood Equations

These are equations fitted to the averaged data of each water harvester design. These equations were fitted using PySR and were designed to minimize the MSE between the two equations, if the Jupyter notebook file present in FLOOD-Data is run again, each would have different results.

MSE:

$$\text{MSE}=\frac{1}{n}\sum_{i=1}^{n}(f(x)-g(x))^{2}$$

Desiccant Control Wheel:

$$\log{\left(1.18^{x + 0.841 \cos{\left(x^{0.974} + 0.155 \right)} + \cos{\left(\left\lceil{x}\right\rceil^{0.553} \right)} \left\lfloor{e^{\text{erf}{\left(x \right)}}}\right\rfloor} + 0.550 x \right)}$$ $$\text{MSE}=2.695e-02$$

NiTi Prototype:

$$x \left(- 0.000675 x - 0.00581 \cos{\left(0.861 \text{erf}{\left(\cos{\left(0.632 x \right)} \right)} + 0.861 \left\lfloor{x - 0.855}\right\rfloor \right)} + 0.214\right)$$ $$\text{MSE}=2.507e-02$$

Deprecated Control:

$$\left\lceil{\log{\left(0.526 x + 2.07 \right)}}\right\rceil \text{erf}{\left(0.0790 x + 0.0790 \sin{\left(0.0924 x \left\lfloor{x + \sin{\left(x \cos{\left(\cos{\left(\text{erf}{\left(\cos{\left(\left(e^{x} + 2.07\right) \left\lceil{\cos{\left(2 e^{\left\lceil{x}\right\rceil + 1} \right)}}\right\rceil \right)} \right)} \right)} \right)} \right)}}\right\rfloor \right)} \right)}$$ $$\text{MSE}=8.403e-03$$

Deprecated Prototype:

$$\log{\left(1.08^{x + 2.39 e^{\sin{\left(x + 0.573 \right)}}} \text{erf}{\left(\sin{\left(\text{erf}{\left(\cos{\left(1.07^{\left\lceil{x + 1.00 \cos{\left(x + 0.771 \right)} + 0.349}\right\rceil} \right)} \right)} \right)} \right)} + 1.14^{x} \right)}^{0.720}$$ $$\text{MSE}=1.869e-02$$

Flood MCU

Instructions for Opening and Building MCU Code

1. Install Visual Studio Code (VS Code): Ensure that you have VS Code installed on your system as per the prerequisites mentioned earlier.
2. Install Platform IO: After successfully installing VS Code, proceed to install Platform IO.
3. Download the Platform IO Directory: Once Platform IO is installed, download the Platform IO directory from the FLOOD-MCU folder.
4. Open the Platform IO Directory in VS Code: After downloading the files, open the directory in VS Code.
5. Navigate to the Platform IO Extension: Within VS Code, navigate to the Platform IO extension.
6. Select the Folder: From the Platform IO extension, choose the 'Pick a folder' option and select the folder that contains the platformio.ini file.
7. Access the main.cpp Program: You can now access the main.cpp program located in the src directory.
8. Ensure Arduino Nano or Uno is Plugged In: To access automatic build deployment, ensure that an Arduino Nano or Arduino Uno is plugged into your system.

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Flood Photos

For this project, all pertinent images are housed in the FLOOD-PHOTOS directory. This directory is organized into the following sub-directories for ease of navigation and access:

1. Proto: This contains images for the final prototype.
2. Control: This includes images for the Control Harvester.
3. Deprecated: This houses the images for designs that are no longer in use.

License

The MIT License (MIT) 2024 - Dr. John LaRocco, Dr. Qudsia Tahmina, John Simonis. Please have a look at the LICENSE.md for more details.

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