Aerodynamics Discuss the concepts of aerodynamics here

Experiment with a new shape of Airfoil for my glider

Old 09-16-2018, 08:16 AM
Thread Starter
Join Date: Aug 2018
Location: i live in chennai, tamil nadu, India
Posts: 123
Default Experiment with a new shape of Airfoil for my glider

I am building an RC glider. It's under construction. I came up with an idea of a sharp leading edge airfoil for that glider.
Click image for larger version

Name:	Airfoil shape.png
Views:	100
Size:	22.7 KB
ID:	186951
This type of airfoils are typically used at supersonic speeds. But to achieve a higher lift to drag ratio, I thought of this symmetric airfoil with sharp leading edge for gliders.

I conducted a small experiment with two chuck gliders. Both identical in dimensions. But one glider having a rounded leading edge and the other having a sharp leading edge. Both being symmetrical.

The sharp leading edge airfoil, due to its less drag kept flying straight, like an arrow everytime I launched it. Here is the video of my experiment.

Now I am going to built a wing with this type of airfoil for my RC glider.
aaindthu is offline  
Old 10-01-2018, 11:23 PM
Super Contributor
quorneng's Avatar
Join Date: Jul 2008
Location: Cheshire, UK
Posts: 2,036

It good to experiment but I am not sure the test was really rigorous enough to confirm that the sharp edged aerofoil was actually better.
For instance are you sure the fact that one flew straight and the other didn't was not due to small differences in the wings?
A sharp edged wing is indeed likely to create less drag than a conventional one when it is generating no lift but the drag will rise more rapidly than the conventional one when it is set at an angle to the airflow necessary to generate lift.
Just keep experimenting!
quorneng is offline  
Old 10-02-2018, 08:12 AM
Super Contributor
CHELLIE's Avatar
Join Date: Oct 2006
Location: Hesperia, So. Calif
Posts: 19,269

it will work, but its not for a slow flying glider, if your plane was going to fly at Mach 2 then it would be ok LOL
CHELLIE is offline  
Old 10-02-2018, 08:21 AM
Super Contributor
solentlife's Avatar
Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Posts: 12,789

There is one inherent problem with sharp LE ... critical angle to airflow.

As Q mentions - there is a sharp change in its ability to sustain lift.

It is actually not correct to say a fast aircraft has a sharp LE ........ what is true is that such aircraft have a THIN wing .... the old EE Lightning is a prime example of this. BUT they still had ROUNDED LE for very good reason.

As the wing angle of attack changes - the LE presents a different attitude to the oncoming airflow. If its rounded - the airflow will remain good for a reasonable change of angle, but make that LE sharp - a small change in angle of attack and now you have a turbulent disrupted airflow.

The sharp entry would only benefit 'maybe' in perfectly straight level flight with no requirement to pitch up / down.

Its actually a phenomenon we see with flat plate wings when you don't sand a rounded LE.

solentlife is offline  
Related Topics
Thread Starter
Last Post
02-16-2016 01:19 AM
Off Topic Chit Chat
09-23-2014 08:48 PM
Joe 1320
Electric Ducted Fan Jets
06-03-2013 03:53 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Quick Reply: Experiment with a new shape of Airfoil for my glider

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

Page generated in 0.08969 seconds with 12 queries