2528df0f75
These changes make it unnecessary to copy header files around during the build process, which tends to confuse IDEs and debuggers. The headers which comprise Cantera's external C++ interface are now in the 'include' directory. All of the samples and demos are now in the 'samples' subdirectory.
57 lines
1.1 KiB
Matlab
Executable file
57 lines
1.1 KiB
Matlab
Executable file
function isentropic(g)
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% ISENTROPIC isentropic, adiabatic flow example
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%
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% In this example, the area ratio vs. Mach number curve is
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% computed for a hydrogen/nitrogen gas mixture.
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%
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help isentropic
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if nargin == 1 & isa(g,'solution')
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gas = g;
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else
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gas = IdealGasMix('gri30.xml');
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end
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% set the stagnation state
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set(gas,'T',1200.0,'P',10.0*oneatm,'X','H2:1,N2:0.1');
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s0 = entropy_mass(gas);
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h0 = enthalpy_mass(gas);
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p0 = pressure(gas);
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mdot = 1; % arbitrary
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mach = [];
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a = [];
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i = 1;
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amin = 1.e14;
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% compute values for a range of pressure ratios
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for r = 0.005:0.0025:0.995
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p = p0*r;
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% set the state using (p,s0)
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set(gas,'P',p,'S',s0);
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h = enthalpy_mass(gas);
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rho = density(gas);
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v2 = 2.0*(h0 - h); % h + V^2/2 = h0
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v = sqrt(v2);
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a(i) = mdot/(rho*v); % rho*v*A = constant
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if a(i) < amin
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amin = a(i);
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end
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mach(i) = v/soundspeed(gas);
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i = i + 1;
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end
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a = a/amin;
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% plot results
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clf;
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plot(mach,a);
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ylabel('Area Ratio');
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xlabel('Mach Number');
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title('Isentropic Flow: Area Ratio vs. Mach Number');
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