||November 28, 2011 13:57
Great lift coefficients but negative drag coefficient?!
Hi as the title suggests I am having trouble with my drag coefficients with varying alpha. I am modelling a naca 2412 in 2D using a c-grid style mesh which shows no errors during checks. I am using the coupled solver,Green-guass cell based, PRESTO! pressure, and second order Momentum. I have also changed my relaxation parameters to both .09 to avoid oscillation. I do not understand how I can have such accurate lift coefficients but horrible drag coefficients. Thanks in advance.