Longitudinal Aircraft Dynamics #2 – 2D polynomial interpolation of parameters cl, cd and cm

05/24/2011

In the previous section, the main wing airfoil and the horizontal stabilizer airfoil were simulated using Xflr5. The three coefficients, lift, drag and moment were then interpolated on charts in Excel using 4th and 5th order polynomials. This section shows a few tricks about how to easily introduce those 60 equations as spreadsheet formulas in Excel ranges. It also presents a simple linear interpolation method across the Reynolds number range. We need to do this since we simulated…

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Longitudinal Aircraft Dynamics #1 – using Xflr5 to model the main wing, the horizontal stabilizer and extracting the polynomial trendlines for cl, cd and cm

05/23/2011

This is a tutorial about using a free aerodynamic modeling package (Xflr5) to simulate two airfoils in 2D (the main wing and the horizontal stabilizer) for ten different Reynolds numbers, then using Excel to extract the approximate polynomial equations of those curves (cl, cd and cm) and based on them, simulate a 2D aircraft as an animated model. This section deals with the aero modeling and the 4th and 5th order polynomial extraction….

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Aerodynamics Naive #3 – a brief introduction to Xflr5, a virtual wind tunnel

05/19/2011

The previous section implemented and charted the ping-pong polar diagrams in a spreadsheet and showed a reasonble similarity, for moderate angles of attack, between these diagrams and the ones modeled using Xflr5, a virtual wind tunner. This section introduce the  concept Reynolds number and it also contains a very brief introduction to Xflr5, the free virtual wind tunnel software.

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Aerodynamics Naive #2 – spreadsheet implementation of the Ping-Pong polar diagrams

05/18/2011

This section of the tutorial implements the lift and drag formulas in a worksheet, creating and charting the polar diagrams for an ultra simplified ping-pong model of an airfoil. Comparing these diagrams with ones obtained by using a virtual wind tunnel (XFLR5) we can see a decent resemblance for moderate angles of attack (smaller than about 8 degrees in absolute value). [sociallocker][/sociallocker]

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Aerodynamics Naive #1 – deriving the Ping-Pong airfoil polar diagrams

05/17/2011

This is the ping-pong aerodynamic analogy. The wing is a ping pong bat and the air is a bunch of evenly spaced array of ping pong balls. It is a naive model but, as we will see in a later post, the polar diagrams derived from this analogy (between -12 to +12 degrees of angle of attack) are surprisingly close shape wise to the real diagrams of a thin, symmetric airfoil. The model of course cannot possibly calculate anything related…

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Anaglyph Charts Demo #2- an animated heat transfer model using a red-cyan wireframe chart

05/12/2011

This is another basic demo investigating the feasibility of using anaglyph wireframes to plot scientiffic data. Open the attached worksheet and with your 3D glasses on, watch the chart. The data is a dynamic temperature map obtained from a 2D heat transfer model in a metal plate. The heat model is complete and you can run it with various parameters. You can hit “Start / Pause” and manually adjust the pitch and…

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Anaglyph Charts Demo #1- creating 3D effects on charts using red-cyan elementary chips (sprites)

05/11/2011

This is a basic demo investigating the feasibility of using anaglyph sprites to plot scientiffic data. Open the attached worksheet and with your 3D glasses on, watch the chart. The data results are various temperature maps obtained from a 2D heat transfer model in a metal plate. You have 4 different selectable mapps there but you can also invert the pattern using the “Flip” button. I find the 3D effect to be decent but not good enough…

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Cosmos Naive – a very basic demo of anaglyph stereoscopy with sprites in Excel

05/09/2011

Reach out for your 3D goggles because this is a representation of the Cosmos through the eyes of a 5-year old. The model displays a few objects at various depths and move two of them back and forth on a chart to demonstrate the stereoscopic effect. Though very simplistic it is an excelent example of anaglyph stereoscopy in action showing you how it’s built. The farther the red and cyan (turquoise)…

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