function 
 
 
   define 
 
 
   % define the stirling engine geometric 
 
 
   % and operational parameters 
 
 
   % Israel Urieli 4/1/02 (April Fool's Day) 
 
 
   % Modified 2/12/2010 to include no-matrix regenerator awgr0 
 
 
   % Modified 7/10/2016 to include betadrive engines 
 
 
   clc; 
 
 
   clear all; 
 
 
   % The set of global variables defined are: 
 
 
   % engine 
 
 
   global 
 
 
   engine_type 
 
 
   % s)inusoidal, y)oke, r)ockerV, b)etadrive 
 
 
   global 
 
 
   vclc vcle 
 
 
   % compression,expansion clearence vols [m^3] 
 
 
   global 
 
 
   vswc vswe 
 
 
   % compression, expansion swept volumes [m^3] 
 
 
   global 
 
 
   alpha 
 
 
   % phase angle advance of expansion space [radians] 
 
 
   global 
 
 
   b1 
 
 
   % Ross yoke length (1/2 yoke base) [m] 
 
 
   global 
 
 
   b2 
 
 
   % Ross yoke height [m] 
 
 
   global 
 
 
   crank 
 
 
   % crank radius [m] 
 
 
   global 
 
 
   dcomp dexp 
 
 
   % diameter of compression/expansion pistons [m] 
 
 
   global 
 
 
   acomp aexp 
 
 
   % area of compression/expansion pistons [m^2] 
 
 
   global 
 
 
   ymin 
 
 
   % minimum yoke vertical displacement [m] 
 
 
   global 
 
 
   conrodc conrode 
 
 
   % length of comp/exp piston connecting rods [m] 
 
 
   global 
 
 
   ycmax yemax 
 
 
   % maximum comp/exp piston vertical displacement [m] 
 
 
   % heatex/cooler 
 
 
   global 
 
 
   vk 
 
 
   % cooler void volume [m^3] 
 
 
   global 
 
 
   ak 
 
 
   % cooler internal free flow area [m^2] 
 
 
   global 
 
 
   awgk 
 
 
   % cooler internal wetted area [m^2] 
 
 
   global 
 
 
   dk 
 
 
   % cooler hydraulic diameter [m] 
 
 
   global 
 
 
   lk 
 
 
   % cooler effective length [m] 
 
 
   % heatex/heater 
 
 
   global 
 
 
   vh 
 
 
   % heater void volume [m^3] 
 
 
   global 
 
 
   ah 
 
 
   % heater internal free flow area [m^2] 
 
 
   global 
 
 
   awgh 
 
 
   % heater internal wetted area [m^2] 
 
 
   global 
 
 
   dh 
 
 
   % heater hydraulic diameter [m] 
 
 
   global 
 
 
   lh 
 
 
   % heater effective length [m] 
 
 
   % heatex/regenerator 
 
 
   global 
 
 
   lr 
 
 
   % regenerator effective length [m] 
 
 
   global 
 
 
   cqwr 
 
 
   % regenerator housing thermal conductance [W/K] 
 
 
   global 
 
 
   matrix_type 
 
 
   % m)esh f)oil n}o matrix 
 
 
   global 
 
 
   vr 
 
 
   % regen void volume [m^3] 
 
 
   global 
 
 
   ar 
 
 
   % regen internal free flow area [m^2] 
 
 
   global 
 
 
   awgr0 
 
 
   % no matrix regenerator wetted area [m^2] 
 
 
   global 
 
 
   awgr 
 
 
   % regen internal wetted area [m^2] 
 
 
   global 
 
 
   dr 
 
 
   % regen hydraulic diameter [m] 
 
 
   % gas 
 
 
   global 
 
 
   rgas 
 
 
   % gas constant [J/kg.K] 
 
 
   global 
 
 
   cp 
 
 
   % specific heat capacity at constant pressure [J/kg.K] 
 
 
   global 
 
 
   cv 
 
 
   % specific heat capacity at constant volume [J/kg.K] 
 
 
   global 
 
 
   gama 
 
 
   % ratio: cp/cv 
 
 
   global 
 
 
   mu0 
 
 
   % dynamic viscosity at reference temp t0 [kg.m/s] 
 
 
   global 
 
 
   t0 t_suth 
 
 
   % reference temp. [K], Sutherland constant [K] 
 
 
   global 
 
 
   prandtl 
 
 
   % Prandtl number 
 
 
   % operat 
 
 
   global 
 
 
   pmean 
 
 
   % mean (charge) pressure [Pa] 
 
 
   global 
 
 
   tk tr th 
 
 
   % cooler, regenerator, heater temperatures [K] 
 
 
   global 
 
 
   freq omega 
 
 
   % cycle frequency [herz], [rads/s] 
 
 
   global 
 
 
   mgas 
 
 
   % total mass of gas in engine [kg] 
 
 
   % new data file 
 
 
   global 
 
 
   new fid 
 
 
   new = input( 
 
 
   'Create a new data file? (y/n)' 
 
 
   , 
 
 
   's' 
 
 
   ); 
 
 
   if 
 
 
   strncmp(new, 
 
 
   'y' 
 
 
   ,1) 
 
 
   filename = input( 
 
 
   'enter new filename: ' 
 
 
   , 
 
 
   's' 
 
 
   ); 
 
 
   fid = fopen(filename, 
 
 
   'w' 
 
 
   ); 
 
 
   else 
 
 
   fid = 0; 
 
 
   while 
 
 
   fid < 1 
 
 
   filename = input( 
 
 
   'open filename: ' 
 
 
   , 
 
 
   's' 
 
 
   ); 
 
 
   [fid, message] = fopen(filename, 
 
 
   'r' 
 
 
   ); 
 
 
   if 
 
 
   fid == -1 
 
 
   display(message) 
 
 
   display( 
 
 
   'press ^C to exit' 
 
 
   ) 
 
 
   end 
 
 
   end 
 
 
   end 
 
 
   engine 
 
 
   heatex 
 
 
   gas 
 
 
   operat 
 
 
   status = fclose(fid);