Development of a Generalized Source Code for NACA Four Digit Airfoils

Development of a Generalized Source Code for NACA Four Digit Airfoils
Development of a Generalized Source Code for NACA Four Digit Airfoils
Bibliographical Metadata
Authors:	Rubiat Mustak

Abstract

An airfoil is a cross section of airplanes wings. It is very much difficult for a researcher to perform his test on the whole aircraft wing. So a test using small cross section of wings or airfoils is performed by researchers. For experimental purposes airfoils need to be constructed. For constructing a real airfoil model an airfoil profile is needed. For obtaining airfoil profiles coordinates are needed. There are many available online sources for these coordinates. But this study will show how someone can obtain required coordinates for drawing airfoil profile without taking any information from online available sources. For obtaining airfoil co ordinates generalized equations for airfoils are used. The whole coordinate generation is performed using programming languages. In this case C programming is used. With the help of these co ordinates generated by c programming it is possible to draw airfoil profiles hence an airfoil profile for NACA-4415 airfoil is also shown. The whole study is based on NACA four digit airfoils. In the same fashion study based on NACA five digit and NACA Six digit can be performed.

Conclusion

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Future work

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Approach

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Implementations

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Research Problem

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Evaluation

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Development of a Generalized Source Code for NACA Four Digit Airfoils

Abstract: An airfoil is a cross section of airplanes wings. It is very much difficult for a researcher to perform his test on the whole aircraft wing. So a test using small cross section of wings or airfoils is performed by researchers. For experimental purposes airfoils need to be constructed. For constructing a real airfoil model an airfoil profile is needed. For obtaining airfoil profiles coordinates are needed. There are many available online sources for these coordinates. But this study will show how someone can obtain required coordinates for drawing airfoil profile without taking any information from online available sources. For obtaining airfoil co ordinates generalized equations for airfoils are used. The whole coordinate generation is performed using programming languages. In this case C programming is used. With the help of these co ordinates generated by c programming it is possible to draw airfoil profiles hence an airfoil profile for NACA-4415 airfoil is also shown. The whole study is based on NACA four digit airfoils. In the same fashion study based on NACA five digit and NACA four digit can be performed.

Keywords Airfoil, Cross section, Source Code ,Wing;

Introduction An airplane is a transportation media with wings having one or more engines that enable it to fly through the air .These wings of airplane creating pressure difference between upper and bottom surfaces which in turn producing lift and helps the airplane to fly [1]. Airfoils are the cross section of these wings. Design of airfoil varies from airplane to airplane [2] .Researchers trying for centuries for classifying these various types of airfoils. Among those U.S. National Advisory Committee for Aeronautics or NACA is more successful. NACA classified airfoils in different groups such as four digit series, five digit series etc. Each series of airfoils has their unique characteristics. Each series of airfoils has their unique design features. Upon growing popularities of NACA airfoils researchers are interested on these airfoils. A lot of investigations are performed in different countries around the world. But most of the investigations used online available coordinates for design or drawing airfoil profiles. This study try to make an exception by doing the design or drawing of airfoils using self originated coordinates using programming languages.

Source Code for Generating Coordinates Using the generalized equations for four digit series a generalized source code is designed. This source code can be written in any programming languages and can be used for all four digit series airfoils. Here the c compiler is choosen.

1. include<stdio.h>
2. include<conio.h>
3. include<math.h>

void main() {

   float yt[2000],yc[2000],yu[2000],yl[2000],xu[2000],xl[2000],t,x[2000],m,p,c,n;
   int f,k;
   printf("please enter the chord length:");
   scanf("%f",&c);
   printf("\n please enter the maximum camber:");
   scanf("%f",&m);
   printf("\n please enter the position of camber from leading edge:");
   scanf("%f",&p);
   printf("\n please enter maximum thickness:");
   scanf("%f",&t);
   printf("How many coordinates you want to generate for drawing profile \n note that:the more coordinates the smoother the profile is?");
   scanf("%f",&n);
   printf("The obtained Coordinate of mean camber line are         While thickness is:");
   for(f=0;f<=n;f++)
   {x[0]=0;
      x[f+1]=x[f]+c/n;}
      for(f=1;f<=n;f++)
   {

printf("\nx[%d]=%f",f,x[f]) ;

   if(x[f]<=p)
  {

   yc[f]=(m/(p*p))*(2*p*x[f]-x[f]*x[f]);}
   if(x[f]>p)
   {
       yc[f]=(m/((1-p)*(1-p)))*(1-2*p+2*p*x[f]-x[f]*x[f]);
       }
   printf("\tyc[%d]=%f",f,yc[f]);
   yt[f]=5*t*(.2969*(sqrt(x[f]))-.1260*x[f]-0.3516*x[f]*x[f]+0.2843*x[f]*x[f]*x[f]-0.1015*x[f]*x[f]*x[f]*x[f]);
  printf("\t\tyt[%d]=%f",f,yt[f]);

   xu[f]=x[f];
   yu[f]=yc[f]+yt[f];
   xl[f]=x[f];
   yl[f]=yc[f]-yt[f];}
   printf("\n The obtained upper surface coordinates are:");
   for(f=1;f<=n;f++)
   {printf("\nxu[%d]=%f   yu[%d]=%f",f,xu[f],f,yu[f]);}

   printf("\n The lower surface coordinates are:");
    for(f=1;f<=n;f++)
  {
   printf("\nxl[%d]=%f   yl[%d]=%f",f,xl[f],f,yl[f]);}

}

The advantage of using this program is that available sources provide only a few coordinates. But using this program someone can have more coordinates than available sources. Which will results in a better airfoil profile .The more points the more smooth profile.

References

[1] Md.Amzad Hossain,Md. Nizam Uddin,Rubiat Mustak,“Experimental Study of Aerodynamic Characteristics Of Airfoils Using Different Shaped Dimples”,The International Journal Of Engineering And Science (IJES) ,Volume 4, Issue 1, Pages PP.13-17 ,2015 [2] Rubiat Mustak, Md. Harun-Or-Rashid Molla and Mohammad Mashud, “Improvement of Aerodynamic Characteristics of an Airfoil by Surface Modification”,American Journal of Engineering Research (AJER),Volume 6,Issue 3,PP.07-14,2017. [3] Rubiat Mustak, Md. Habib Ullah Khan, Md. Harun-Or-Rashid Molla,“Design and construction of NACA-4415 airfoil with various shaped surface modifications”, Asia Pacific Journal of Engineering Science and Technology(APJEST),Volume-3,Issue-1,PP.28-38,2017.