1 / 17

Scientific Programming

Scientific Programming. Class 14. Today’s Assignment:.

rianne
Télécharger la présentation

Scientific Programming

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Scientific Programming Class 14

  2. Today’s Assignment: • The most common model for a reciprocating engine is the slider-crank mechanism shown. Dimensions of a representitive crank are shown. If the crank OB has a constant clockwise1500 RPM rotational speed, the piston will reach its maximum velocity between 0 < q < 180o. Write a Fortran Program that will write out the maximum velocity and the crank angle, q, at which it occurs. • VA = OB SIN(q) (1 + (OB/AB) COS(q) / (1 - (OB/AB)2 SIN2(q))1/2) w

  3. Piston Speed vs Crank Angle

  4. Program: • PROGRAM slidercrank • IMPLICIT NONE • REAL:: ob,ab,angle,angleinc,radian,radianinc,omega,v,va,vb • ob = 5. • ab = 14. • omega = 1500.*2.*(4.*ATAN(1.))/60. • angle = 0. • angleinc = 1. • radianinc = angleinc*(4.*ATAN(1.))/180. • WRITE(*,3) 3 FORMAT(12x,'angle',14x,'max speed',/,12x,'(deg)',14x,'(in/sec)') • DO • radian = angle*(4.*ATAN(1.))/180. • v = ob*SIN(radian)*(1 + (ob/ab)*COS(radian)/(SQRT(1 - ((ob/ab)**2)*((SIN(radian))**2))))*omega • va = ob*SIN(radian-radianinc)*(1 + (ob/ab)*COS(radian-radianinc)/(SQRT(1 - ((ob/ab)**2)*((SIN(radian-radianinc))**2))))*omega • vb = ob*SIN(radian+radianinc)*(1 + (ob/ab)*COS(radian+radianinc)/(SQRT(1 - ((ob/ab)**2)*((SIN(radian+radianinc))**2))))*omega • IF (v>va.AND.v>vb)THEN • WRITE(*,5)angle, v 5 FORMAT(10X,F6.0,12X,F10.2) • ELSE • END IF • IF (angle>=180.) EXIT • angle = angle + angleinc • END DO • END

  5. Program Results: • angle max speed • (deg) (in/sec) • 72. 834.61 • The tolerance on the angle is +- 1o.

  6. Bonus Exercises: • One to three bonus points will be awarded for each correct answer to the question posed on each of the following slides. • Each exercise will be left on the screen for 5 minutes.

  7. Bonus Exercise 1: • Describe each of the following Combinational Logical Operators • L1.AND.L2 • L1.OR.L2 • L1.EQV.L2 • L1.NEQV.L2 • NOT.L1

  8. Bonus Exercise 2: • Describe the operation of the following IF Block. • IF (logical expression 1) THEN • Statement 1 • Statement 2 • ….. • ELSE IF (logical expression 2) THEN • Statement 3 • Statement 4 • ….. • ELSE • Statement 5 • Statement 6 • ….. • END IF • Next line of code

  9. Bonus Exercise 3 : • Describe the operation of the following • The While Loop • The DO WHILE Loop • The Iterative Loop • CYCLE Statement • EXIT Statement

  10. New Stuff – Selected Topics • Formatted Read Statements • Creating, Writing To & Reading From Files

  11. Formatted Read Statements • Read(*,*) a, b, c • or, • Read(*,10) a, b, c • 10 Format(5X,3F10.2) • Input Buffer Line • * - Default Input Device – Keyboard • * - Default Output Device - Monitor

  12. Creating A File On The Hard Drive • OPEN (list of clauses) • CLOSE (list of clauses) • Clauses: • UNIT= integer expression • FILE=‘character expression’ • IOSTAT=integer expression • ….. many, many more

  13. Creating A File On The Hard Drive • OPEN (UNIT=iounit, FILE=‘filename’,IOSTAT=ierror) • CLOSE (UNIT=iounit) • In between opening & closing a file, you may read from & write to it using its unit number. • WRITE(iounit,5) • REWIND(UNIT=iounit, IOSTAT=ierror) • READ(iounit,5,IOSTAT=ierror) • 5 FORMAT

  14. Creating A File On The Hard Drive • PROGRAM dummy • IMPLICIT NONE • REAL:: v, vs, a, r, g, mach, n • INTEGER:: iounit, ierror • iounit = 10 • OPEN(UNIT=iounit, FILE='radius‘, IOSTAT=ierror) • WRITE(*,5) • WRITE(iounit,5) • 5 FORMAT(//8X,'Aircraft Turning Radius') • WRITE(*,6) • WRITE(iounit,6) • 6 FORMAT(8X,'Mach No = .85 : V = 289.3 (m/s) : Vs = 340.3 (m/s)'/) • WRITE(*,8) • WRITE(iounit,8) • 8 FORMAT(8X,'Multiple of g',5X,'Acceleration (m/s2)',3X,'Turning Radius (m)') • g = 9.81 • mach = 0.85 • vs = 340.3 • v = mach*vs • n = 2. • DO • a = n*g • r = v**2/a • WRITE(*,10)n,a,r • WRITE(iounit,10)n,a,r • 10 FORMAT(10X,F6.2,9X,F12.3,9x,F12.3) • n = n + .5 • IF (n==8.5) EXIT • END DO • CLOSE(UNIT=iounit) • END

  15. Contents of the file, “radius”, on the hard drive • Aircraft Turning Radius • Mach No = .85 : V = 289.3 (m/s) : Vs = 340.3 (m/s) • Multiple of g Acceleration (m/s2) Turning Radius (m) • 2.00 19.620 4264.447 • 2.50 24.525 3411.558 • 3.00 29.430 2842.965 • 3.50 34.335 2436.827 • 4.00 39.240 2132.224 • 4.50 44.145 1895.310 • 5.00 49.050 1705.779 • 5.50 53.955 1550.708 • 6.00 58.860 1421.482 • 6.50 63.765 1312.138 • 7.00 68.670 1218.414 • 7.50 73.575 1137.186 • 8.00 78.480 1066.112

  16. Reading From A File On The Hard Drive • PROGRAM readwrite • IMPLICIT NONE • REAL:: x, y, z • INTEGER:: iounit, ierror • iounit = 9 • OPEN(UNIT=iounit,FILE='readfile',IOSTAT=ierror) • x = 2. • y = 4. • z = 9. • WRITE(iounit,10)x,y,z • REWIND(UNIT=iounit, IOSTAT=ierror) • 10 FORMAT(1X,3F5.1) • READ(iounit,*,IOSTAT=ierror)a,b,c • WRITE(*,*)a,b,c • CLOSE(UNIT=iounit) • END • 2.000000 4.000000 9.000000

  17. Assignment: • Read and understand the material in this slide set • Search out information (internet or printed references) and examples on: • how to create files • how to write to them • how to read them

More Related