Switch to YAML files for PMA props

+ Refactoring of prop_pma function.

prop/buckley.yaml

@@ -0,0 +1,12 @@
+# APM parameters from Buckley et al.
+
+name: buckley
+r2: 0.025           # outer electrode radius [m]
+r1: 0.024           # inner electrode radius [m]
+L: 0.1              # length of APM [m]
+RPM: 13350          # rotational speed [rpm]
+omega: RPM*2*pi/60  # rotational speed [rad/s]
+omega_hat: 1        # APM, so rotational speed is the same
+Q: 1.02e-3/60       # aerosol flowrate [m^3/s]
+T: 298              # system temperature [K]
+p: 1                # system pressure [atm]

prop/ehara.yaml

@@ -0,0 +1,10 @@
+# APM parameters from Ehara et al.
+
+name: ehara
+r2: 0.103       # outer electrode radius [m]
+r1: 0.1         # inner electrode radius [m]
+L: 0.2          # length of APM [m]
+omega_hat: 1    # APM, so rotational speed is the same
+Q: 0.5/1000/60  # aerosol flowrate [m^3/s], assumed
+T: 298          # system temperature [K]
+p: 1            # system pressure [atm]

prop/kuwata.yaml

@@ -0,0 +1,9 @@
+# Properties from Kuwata
+
+r2: 0.052     # outer electrode radius [m]
+r1: 0.05      # inner electrode radius [m]
+L: 0.25       # classifier length [m]
+omega_hat: 1  # APM conditions
+Q: 1.67e-5    # aerosol flowrate [m^3/s]
+T: 295        # system temperature [K]
+p: 1          # system pressure [atm]

prop/olfert-collings.yaml

@@ -0,0 +1,13 @@
+# Parameters from Olfert and Collings
+# Nearly identical to the Ehara et al. case
+
+name: olfert-collings
+r2: 0.103                 # outer electrode radius [m]
+r1: 0.1                   # inner electrode radius [m]
+L: 0.2
+omega_hat: 0.945
+Q: 0.5/1000/60            # aerosol flowrate [m^3/s]
+T: 295                    # system temperature [K]
+p: 1                      # system pressure [atm]
+m0: 900 * pi / 6 * 1e-27  # copy mass-mobility relation info (only used to find Rm)
+Dm: 3

prop/olfert.yaml

@@ -0,0 +1,10 @@
+# Default CPMA parameters from Olfert lab
+
+name: olfert
+r1: 0.06          # inner electrode radius [m]
+r2: 0.061         # outer electrode radius [m]
+L: 0.2            # length of chamber [m]
+p: 1              # pressure [atm]
+T: 293            # system temperature [K]
+Q: 3/1000/60      # volume flow rate [m^3/s]
+omega_hat: 32/33  # ratio of angular speeds

prop_pma.m

@@ -10,101 +10,115 @@
 
 function [prop] = prop_pma(spec)
 
-if ~exist('spec', 'var') % if type of property set is not specified
-    spec = 'olfert';
-elseif isempty(spec)
-    spec = 'olfert';
-end
+% if type of property specification is not given, use 'olfert'.
+if ~exist('spec', 'var'); spec = []; end
+if isempty(spec); spec = 'olfert'; end
 
 %-- Default mass-mobility information -------------%
+% Default, Dm = 3 corresponds to spheres (no change in effective density).
 prop.Dm = 3; % mass-mobility exponent
 prop.m0 = 4.7124e-25; % mass-mobility pre-factor
 
 % Universal relation (Olfert and Rogak)
 % prop.Dm = 2.48;
 % prop.m0 = 2.9280e-24;
 
-switch spec
-
-    %-- CPMA parameters from Olfert lab ----------------------------------%
-    case 'olfert'
-        prop.r1 = 0.06; % inner electrode radius [m]
-        prop.r2 = 0.061; % outer electrode radius [m]
-        prop.L = 0.2; % length of chamber [m]
-        prop.p = 1; % pressure [atm]
-        prop.T = 293; % system temperature [K]
-        prop.Q = 3/1000/60;%0.3/1000/60;%1.5/1000/60; % volume flow rate (m^3/s) (prev: ~1 lpm)
-        prop.omega_hat = 32/33; % ratio of angular speeds
-
-    %-- CPMA/APM parameters from Buckley et al. --------------------------%
-    case 'buckley'
-        prop.r2 = 0.025; % outer electrode radius [m]
-        prop.r1 = 0.024; % inner electrode radius [m]
-        prop.L = 0.1;    % length of APM [m]
-        RPM = 13350; % rotational speed [rpm]
-        prop.omega = RPM*2*pi/60; % rotational speed [rad/s]
-        prop.omega_hat = 1; % APM, so rotational speed is the same
-        prop.Q = 1.02e-3/60; % aerosol flowrate [m^3/s]
-        prop.T = 298; % system temperature [K]
-        prop.p = 1; % system pressure [atm]
-
-    %-- APM parameters from Ehara et al. -------------%
-    case 'ehara'
-        prop.r2 = 0.103; % outer electrode radius [m]
-        prop.r1 = 0.1; % inner electrode radius [m]
-        prop.L = 0.2;    % length of APM [m]
-        prop.omega_hat = 1; % APM, so rotational speed is the same
-        prop.Q = 0.5/1000/60; % aerosol flowrate [m^3/s], assumed
-        prop.T = 298; % system temperature [K]
-        prop.p = 1; % system pressure [atm]
-
-    %-- Parameters from Olfert and Collings -------------%
-    %   Nearly identical to the Ehara et al. case
-    case 'olfert-collings'
-        prop.r2 = 0.103; % outer electrode radius [m]
-        prop.r1 = 0.1; % inner electrode radius [m]
-        prop.L = 0.2;
-        prop.omega_hat = 0.945;
-        prop.Q = 0.5/1000/60; % aerosol flowrate [m^3/s]
-        prop.T = 295; % system temperature [K]
-        prop.p = 1; % system pressure [atm]
-
-        prop.m0 = 900 * pi / 6 * 1e-27; % copy mass-mobility relation info (only used to find Rm)
-        prop.Dm = 3;
-
-    %-- Parameters from Kuwata --------------------------%
-    case 'kuwata'
-        prop.r2 = 0.052; % outer electrode radius [m]
-        prop.r1 = 0.05; % inner electrode radius [m]
-        prop.L = 0.25;
-        prop.omega_hat = 1;
-        prop.Q = 1.67e-5; % aerosol flowrate [m^3/s]
-        prop.T = 295; % system temperature [K]
-        prop.p = 1; % system pressure [atm]
-
-    otherwise
-        error(['PMA properties not available for provided case. ',...
-            'Try a different string in the `prop_pma(str)` call.']);
 
-end
+% Read case-specific properties from YAML file.
+% Uses read_yaml(...) method given as a subfunction in this file.
+prop = read_yaml(['prop', filesep, spec, '.yaml'], prop);
 
 
 %-- Parameters related to CPMA geometry ----------------------------------%
-prop.rc = (prop.r2+prop.r1)/2;
-prop.r_hat = prop.r1/prop.r2;
-prop.del = (prop.r2-prop.r1)/2; % half gap width
+prop.rc = (prop.r2 + prop.r1) / 2;
+prop.r_hat = prop.r1 / prop.r2;
+prop.del = (prop.r2 - prop.r1) / 2; % half gap width
 
-prop.A = pi*(prop.r2^2-prop.r1^2); % cross sectional area of APM
-prop.v_bar = prop.Q/prop.A; % average flow velocity
+prop.A = pi * (prop.r2 ^ 2 - prop.r1 ^ 2); % cross sectional area of APM
+prop.v_bar = prop.Q / prop.A; % average flow velocity
 
 
 %-- For diffusion --------------------------------------------------------%
 kB = 1.3806488e-23; % Boltzmann's constant
-prop.D = @(B) kB.*prop.T.*B; % diffusion coefficient
+prop.D = @(B) kB .* prop.T .* B; % diffusion coefficient
 
 
 % Fill mass-mobility relation equivalents.
 prop = prop_massmob(prop);
 
 end
 
+
+
+
+% READ_YAML  Simple utility to read simple YAML files.
+%  
+%  AUTHOR: Lloyd Russell, 2017
+%  REPO: https://github.com/llerussell/ReadYAML
+%  MODIFIED: Timothy Sipkens, 2021-04-19
+function prop = read_yaml(file_path, prop)
+
+% Parse inputs (currently never invoked).
+if ~exist('prop', 'var'); prop = []; end
+if isempty(prop); prop = struct(); end
+
+% If file of presets does not exist.
+if ~isfile(file_path)
+    error(['PMA properties not available for provided case. ',...
+            'Try a different string in the `prop_pma(str)` call.']);
+end
+
+
+% Read file line by line.
+fid = fopen(file_path, 'r');
+data = textscan(fid, '%s', 'delimiter', '\n', 'whitespace', '');
+fclose(fid);
+
+% Remove empty lines.
+data = deblank(data{1});
+data(cellfun('isempty', data)) = [];
+
+% Prepare final results structure.
+results = [];
+
+% Parse the contents (line by line).
+for i = 1:numel(data)
+
+    % extract this line
+    thisLine = data{i};
+
+    % ignore if this line is a comment
+    if strcmpi(thisLine(1), '#')
+        continue
+    end
+
+    % find the seperator between key and value
+    sepIndex = find(thisLine==':', 1, 'first');
+
+    % get the key name (remove whitespace)
+    key = strtrim(thisLine(1:sepIndex-1));  
+
+    % get the value, ignoring any comments (remove whitespace)
+    value = strsplit(thisLine(sepIndex+1:end), '#');
+    value = strtrim(value{1}); 
+
+    % attempt to convert value to numeric type
+    [convertedValue, success] = str2num(value);
+    if success
+        value = convertedValue;
+    end
+
+    % store the key and value in the results
+    results.(key) = value;
+end
+
+% Append to supplied structure.
+% Overwrite duplicate fields. 
+f_results = fields(results);
+for ii = 1:length(f_results)
+    prop.(f_results{ii}) = results.(f_results{ii});
+end
+
+end
+
+