Flare-it

Use this free software to assist you in what size port and flare combination you need

Flare-it was written to incorporate all the finding of my experiments into flared ports performance. It provides an easy way to determine what sized port / flare combination will be required to ensure that your ports are noise free.

Simple mode

You only need to input port diameter and flare radius. Flare-it will show the usable and limiting velocities for a range of frequencies.

The blue line shows the velocity you can use at each frequency before boundary layer turbulence occurs (ie "chuffing"). This line moves as flare size or port diameter is changed

The red line shows the velocity you can use at each frequency before Core turbulence and compression occurs. This line only moves as port diameter is changed

The "Nudge" arrows under the Flare radius field, allow you to vary the flare size without having to click the "Calculate" button each time

As you increase flare size, the blue line moves up. There is no point in choosing a flare so large that the blue line appears above the red line

The status line lists the two velocities, initially at 28hz. Clicking on the graph changes the tracking frequency.

If you already have a box design, it's worth switching to Full mode

"Simple" mode of operation

Full mode

By telling Flare-it the velocities required by your design at four frequencies, the software can automatically find the minimum flare radius required.

Enter the port diameter and number of ports.

Uncheck "Cruise control" and enter the four required velocities - refer to your design software to obtain these. WinISD users will need the Pro version.

Tick "Cruise control" to lock in your design. You will not be able to engage "Cruise control" if the port diameter is zero or has an incorrect format

When you change the number of ports or the diameter, "Cruise control" calculates the new velocities required to flow the same volume of air. This allows you to instantly see how different port arrangements would perform in your design.

Make sure the "Calculate minimum" option is selected, and press the "Calculate" button.

"Full" mode of operation

Flare-it will automatically analyse the minimum flare radius for each of the four frequencies and then select the largest radius.

The four required velocities are plotted as black crosses joined by the grey line.

Clicking the graph updates the status line with velocities for the selected frequency. This doesn't track in the same way as simple mode however, because the status line is used to reflect how well the port deals with the required velocities

Selecting the "Manually specify flare radius" option allows you to vary the flare size.

Increasing flare size opens a gap between the blue and grey lines, showing how you can build some port headroom into your design.

Options

An options page allows selection of a 25% allowance for seating position, and a content allowance of either 15% for music or 30% for Home Theatre, for both boundary and core chuffing.

The default options are to include allowances for seating position and masking by content (HT), when determining boundary layer chuffing, but to use no allowances when determining limiting velocity. This allows smaller flares and minimises compression.

Your options and data are automatically saved when you exit

The small graphic at the bottom of the screen changes as different options are selected. This is repeated on the main screen as a reminder of the currently active allowances.

Options screen

General

• Both Imperial and metric measurements are supported. Click on "Change Units" if you prefer to work in inches.
  
  
• Flare-it is shipped with some dummy data and Cruise control engaged, so you can have a play straight away
  
  
• Changes to the software are tracked in the Version notes.

• Determine minimum flare size for a given velocity profile
  
  
• Determine velocity for onset of compression
  
  
• Change port diameters and "Cruise control" automatically finds the new velocities
  
  
• Selectable allowances for masking by content
  
  
• Supports both Imperial and metric measurements

Flare-it is written in Visual Basic 6 and runs under Windows. If you don't have them installed, you may need to grab the VB6 Runtimes - Windows XP already has them.

Filesize 258,048 bytes