100 ! PULSE.PGM - 18 MAR 97
110 ! Algorithm computes injector-open time for stoichiometric combustion.
120 ! This is intended to be demonstrative, not efficient. STP is assumed.
130 IMAGE ###.## Cfm  ##.## ml/sec  ##.# l/h
140 !
150 DISPLAY ERASE ALL,"Displacement (in):";CUBES;:ACCEPT AT(20)SIZE(-5),CUBES
160 DISPLAY ERASE ALL," Rpm:";RPM;:ACCEPT AT(7)SIZE(-4),RPM
170 DISPLAY ERASE ALL," MAP (inches of H2O):";MAP;:ACCEPT AT(23)SIZE(-5),MAP
180 !
190 CFM=(CUBES/2)*RPM*(MAP/406.8)/1728!
200 !
210 ! CUBES/2 because it's a four cycle. 14.7 psi = 406.8 inches of water.
220 ! 1728 cubic inches = 1 cubic foot.
230 !
240 FUEL_VOL=CFM*1728/8850!                      ; cubic inches of fuel per min
250 FUEL=FUEL_VOL*16.3871/60!                    ; fuel in ml/sec
260 HOUR=INT((FUEL*3.6)*10^1+.5)/10^1!           ; fuel consumption per hour
270 !
280 DISPLAY ERASE ALL,USING,130 INT(CFM*100+.5)/100;INT(FUEL*100+.5)/100;HOUR
290 PAUSE
300 !
310 IMAGE " Inj: .#### sec  .### cycle"
320 !
330 DISPLAY ERASE ALL,"Orifice dia (in) : ";D;!  ; injector nozzle diameter
340 ACCEPT AT(21)SIZE(-4),D
350 !
360 CD=1! Coefficient of discharge. This has to do with flow through small
370 !     orifices at lower pressures than we are concerned with here.
380 W=45!                                        ; fuel density in lbs/ft^3
390 DISPLAY ERASE ALL,"Fuel pressure (psi):";FUEL_P;
400 ACCEPT AT(22)SIZE(-5),FUEL_P!                ; usually 30-32 psi
410 DELTA_P=(FUEL_P*27.6807)+MAP!                ; convert to inches of H2O
420 A=PI*(D/2)^2!                                ; injector nozzle area
430 F=CD*A*(10.4*32.2*W*DELTA_P)^(1/2)!          ; fuel flow in lbs/sec
440 F_VOL=F*628.64!                              ; vol in ml/sec
450 PULSE=FUEL/F_VOL!                            ; injector open time
460 TIME=2/(RPM/60)!                             ; 1 complete 4-cycle
470 !
480 DISPLAY ERASE ALL,USING,310 INT(PULSE*10^4+.5)/10^4,INT(TIME*10^3+.5)/10^3
490 PAUSE
500 DISPLAY ERASE ALL," Vol eff:";INT((MAP*100/406)*10+.5)/10;"%"
510 PAUSE:GOTO 150
520 !
530 ! The INT() functions in the DISPLAY statements round the values 
540 ! to N significant digits as follows:
550 !
560 !        ROUNDED_VALUE=INT(VALUE*10^N+.5)/10^N
570 !
580 ! Anything after a ! is a comment and does not need to be entered to RUN.
590 !
600 DISPLAY ERASE ALL," Rpm:";RPM;:ACCEPT AT(7)SIZE(-6),RPM
601 IMAGE #####.
610 DISPLAY ERASE ALL," In duration @ .050 :";DUR;:ACCEPT AT(23)SIZE(-4),DUR
620 TIME=10^6/(RPM/60)!                          ; in microseconds
630 IN_OPEN=TIME*DUR/360
640 DISPLAY ERASE ALL," In open:";INT(IN_OPEN+.5);"uS";
645 DISPLAY "   1";CHR$(223);":";INT((TIME/360)+.5);"uS"
660 PAUSE:GOTO 600