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Port Size Calculator (In progress)

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Edit | 4/10/21 | Added link to version 1: https://1drv.ms/x/s!AjEnAKukzb3Ecv0rRvXI47Xawt0?e=D0phdY

- This version will keep port area constant after you input some variables like port length, dimensions and amount of common walls (explanation here)

- Limitations: Currently does not allow you to input multiple baffles so if you have more than the thickness of material in baffle thickness your displacements will be overstated in regards to displacements from inner port walls. 

- Will allow you to input a slot port design that gets to a desired port area (found to work in another program like WinISD) and compare the other types of ports to it. 



Hey guys when I go to design ports I like seeing the displacement each may cause, albeit a slot port, aero, or anything in between. Although most will not have a need to use this as it requires you already know the cross sectional port area and length you desire, I feel this could be useful in comparing different designs on the fly. Why crunch the math when a computer can do it for you? As of right now I am still working on a dashboard to incorporate for an online tool, but I have all the formulas done for calculating different port types with the same area as a given slot port (eventually plan on adding some more features as time permits). 


For right now I'll just attach screenshots of the in progress build:


Here what the rough input screen will include (will be creating a dashboard for final product):


Variables Required
0.750 Thickness of Port Wall (Inches)
  3/16 Thickness of Circular Port
25.000 Desired Port Length
Y/N Slot Port Design / Enter Desired Port Area*
3.00 Common Walls (If slot port)
longest Is Common Wall on longest side or shortest side? (Applies only to 1 Common Wall Slot Ports)
13.000 Desired Port Height
3.250 Desired Port Width
#### Number of Ports*



From there I have created a table for each design of port that includes the dimensions of each port, along with the displacements of each (this interior displacement number only includes the displacements inside the box for the port design, not the part of the port that is inside your baffle or outside of your box). 


I think eventually I will host it over excel online or google sheets, but please feel free to check my work. *Note for all displacement calculations I assumed 0.75" of port length was not included since it would be apart of the exterior wall, and not part of interior displacements, so the port length for all displacement calculations should be 25-.75 or 24.25" with every port having an assumed material thickness of 0.75" except for aero ports, they are 3/16 but I forgot to add in that material thickness 🤦‍♂️.







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So I managed to create the dashboard today. It allows you to enter in common variables and see dynamically the changes it has on the different port styles. The table to the right shows the displacement for each port style, including the thickness of the panels. Also shows the surface area of each style of port if you wanted to know. I also made sure to have the measurements in both imperial and metric for anyone who might be using hornresp ;). The only limitation this has is I haven't added a way to make a slot port double thick, and the displacements assume you inlet the ports into a exterior baffle - hence why the thickness of the port wall is subtracted from the port length except for the aero ports (they are the full port length entered). 


With these two photos you can see the effect of going from 0 common walls to 3 with a standard slot port. Nearly 0.237 of a cubic foot just by designing the port to make use of the exterior walls. :) I will eventually post a link to an online test version to help work out any bugs.

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Here you can see the complete dashboard that will show you the dimensions of the ports if you were going to build them. I will be making a dedicated screen for those who want to make an hexagon or octagon port with graphics to explain what dimensions to use. Other wise you can just look at the dimensions to build the rectangular port (each side is the same) or the circular ports by the given diameter. I also added for shits and giggles an 80% circular port area for those who want to skimp on their area because they have a more efficient port 🤦‍♂️

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  • 10 months later...

Alright here is the first online version of the calculator:


Hexagonal port screens been chopped for now since it will require some macro/coding that I won't be setting up for now but the actual measurements are there still, interior and exterior. 


I prefer Excel but you shouldn't need a Microsoft account to open the link or edit the input fields. It will update in real time so if multiple people try to edit it at once you will run into issues so please be patient.


Pasting link here and adding to first comment in post ^

Link: https://lcc.click/1mjX81f


The proper way to utilize this is to use it alongside a box program like WinISD. Just work your way down the list of inputs and ignore the last one if your using a standard 3 common wall slot port. Then you will see a comparison of the internal displacements as well as surface area for various port types. *Imoh you are better off doing either Slot port, aero port or rectangular. The other hexa/octo/etc. ports are purely for style and offer only marginal benefits when compared to the others.


Essentially this calculator will only help you decide on what style of port will have the least displacements and surface area that you are comfortable with. It will keep port area constant so you can decide based off purely displacement and surface area (port area * length). 


It is not 100% accurate due to some displacement math being different for differing port designs (aka straight ports vs L-shaped ports have different volumes associates with inner and outer walls). However, it will help you decide if you can fit that extra bit of port area by playing with dimensions of the port. Assumptions are listed, and the math is under sheet "BTS" I plan on expanding on this version so if you have anything you want added just drop a comment.

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