This preview shows pages 1–4. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Progress Report #2 Purdue University Mars Airfoil Research David N. Loffing July 13, 2001 Aerospace Sciences Laboratory Introduction: The purpose of this research project is to investigate the phenomena associated with lowReynolds number aerodynamics. Two airfoils will be used in this study. The first being the Eppler 387 airfoil, used for calibration and validation of data acquisition methods. The second airfoil named PUMA5.106 is a new design intended to be used on a Mars aircraft. Both of this airfoils will be made into rectangular wing models and placed into the Boeing subsonic wind tunnel. Data will be acquired through a balance, a hotfilm wake survey and temperature sensitive paint applied to the airfoil surface to investigate the boundary layer. Wake Survey Data Reduction: The wake survey will be conducted by traversing a hotfilm anemometer downstream of the airfoil measuring the velocity profile of the wake. The velocity deficit within the wake can be related to the profile drag of the airfoil by applying conservation of momentum and continuity to a control volume surrounding the model. For the purpose of this study the method developed by Jones 1 will be used. The control surface has three crosssections. The first is the free stream located in front of the body. The second cross section is located a short distance from the body and is where the measurements are to be taken. The third (designated I for discussion purposes) is located far behind the body such that the static pressure at this crosssection is equal to that of the free stream. The profile drag of the airfoil is equal to the momentum loss at a location, or: dy dy 1 II: P 2 , g 2 , g , U I: P 1 = P Figure 1: Control volume of test section. ) 1 ( sec velocity in change mass D = ) 2 ( ) ( = V U Vda D Where D is drag, U is the initial air speed and V is the air speed at some location within the control surface. Equation 2 is applied to the crosssection I and is also reduced to a single integral by treating the problem as twodimensional with a constant unit span. ) 3 ( ) ( 1 1 1 = dy u U u b D In order to restrict the finding of u 1 to the results found in crosssection II, the continuity equation is applied along a streamline. ) 4 ( 2 1 1 dy u dy u = Substitution of equation 4 into equation 3 results in the drag equation related to the velocities at each crosssection: ) 5 ( ) ( 1 2 dy u U u b D = According to Jones 1 we assume that the flow proceeds from section II to section I without total pressure losses, i.e. g 2 = g 1 . From Bernoullis equation we are able to reduce the velocity terms into pressure values....
View
Full
Document
This note was uploaded on 01/15/2012 for the course AAE 490 taught by Professor Andrisani during the Fall '09 term at Purdue UniversityWest Lafayette.
 Fall '09
 ANDRISANI

Click to edit the document details