chore: improve documentation on defining compressor charts using CURV…

…E and CURVES

docs/docs/about/modelling/setup/models/compressor_modelling/compressor_charts/index.md

@@ -5,7 +5,7 @@ description: Introduction into compressor charts
 ---
 
 # Compressor chart
-The compressor chart is used to setup a model of each compressor. eCalc™ currently support four ways to setup a
+The compressor chart is used to set up a model of each compressor. eCalc™ currently support four ways to set up a
 compressor chart
 
 - Predefined single speed chart
@@ -15,7 +15,7 @@ compressor chart
 
 ## User defined single speed compressor chart
 
-The single speed chart type allows a single compressor curve for one speed.
+The single speed chart type allows a single compressor curve for one speed, using the keyword [CURVE](../../../../../references/keywords/CURVE.md)
 
 ### Format
 ~~~~~~~~yaml
@@ -69,7 +69,7 @@ CURVE:
 ~~~~~~~~
 :::
 ## User defined variable speed compressor chart
-The variable speed chart type allows a fully defined compressor chart with data for two or more speeds. The upper and
+The variable speed chart type allows a fully defined compressor chart with data for two or more speeds, using the keyword [CURVES](../../../../../references/keywords/CURVES.md). The upper and
 lower speed curves will be interpreted as the speed capacity limits for the chart. 
 Whilst the lowest rate points on each of the upper and lower speed curves will define the minimum flow line for the compressor. 
 

docs/docs/about/references/keywords/CURVE.md

@@ -0,0 +1,49 @@
+# CURVE
+
+## Description
+
+When using a detailed single speed compressor model, it is necessary to specify the single speed [COMPRESSOR CHART](../../modelling/setup/models/compressor_modelling/compressor_charts/index.md#user-defined-single-speed-compressor-chart). This can be defined from a .csv file, or it can be defined directly in the YAML file. 
+In either case, the keyword `CURVE` needs to be used. If a .csv file is being used, under the `CURVE` keyword, `FILE` must be used. If specified directly in the YAML file, `SPEED`, `RATE`, `HEAD` and `EFFICIENCY` must be defined.
+
+## Format
+
+~~~~yaml
+MODELS:
+  - NAME: <name of chart, for reference>
+    TYPE: COMPRESSOR_CHART
+    CHART_TYPE: SINGLE_SPEED
+    ...
+    CURVE:
+      - SPEED: <shaft speed for this curve, a number>
+        RATE: <list of rate values for this chart curve>
+        HEAD: <list of polytropic head values for this chart curve>
+        EFFICIENCY: <list of polytropic efficiency values for this chart curve>
+
+  - NAME: <name of chart, for reference>
+    TYPE: COMPRESSOR_CHART
+    CHART_TYPE: SINGLE_SPEED
+    ... 
+    CURVE:
+       - FILE: <filepath to compressor curve>
+~~~~
+
+## Example
+
+~~~~yaml
+MODELS:
+  - NAME: predefined_single_speed_compressor_chart
+    TYPE: COMPRESSOR_CHART
+    CHART_TYPE: SINGLE_SPEED
+    ...
+    CURVE:
+      - SPEED: 7500
+        RATE: [2900, 3503, 4002, 4595.0]
+        HEAD: [8412.9, 7996, 7363, 6127]
+        EFFICIENCY: [0.72, 0.75, 0.74, 0.70]
+
+  - NAME: compressor_chart
+    TYPE: COMPRESSOR_CHART
+    ... 
+    CURVE:
+       - FILE: compressor_chart.csv
+~~~~

docs/docs/about/references/keywords/CURVES.md

@@ -2,25 +2,30 @@
 
 ## Description
 
-When using a detailed compressor model, it is necessary to specify the [COMPRESSOR CHART](../../modelling/setup/models/compressor_modelling/compressor_charts/index.md). This can be defined from a .csv file, or it can be defined directly in the YAML file. If it is defined directly in the YAML file,
-
-In either case, the keyword `CURVES` needs to be used. If an .csv file is being used, under the `CURVES` keyword, `FILE` must be used. If specified directly in the YAML file, `SPEED`, `RATE`, `HEAD` and `EFFICIENCY` must be defined.
+When using a detailed variable speed compressor model, it is necessary to specify the variable speed [COMPRESSOR CHART](../../modelling/setup/models/compressor_modelling/compressor_charts/index.md#user-defined-variable-speed-compressor-chart). This can be defined from a .csv file, or it can be defined directly in the YAML file. 
+In either case, the keyword `CURVES` needs to be used, and curves for at least two different speeds must be defined. If a .csv file is being used, under the `CURVES` keyword, `FILE` must be used. If specified directly in the YAML file, `SPEED`, `RATE`, `HEAD` and `EFFICIENCY` must be defined for each speed.
 
 ## Format
 
 ~~~~yaml
 MODELS:
   - NAME: <name of chart, for reference>
     TYPE: COMPRESSOR_CHART
+    CHART_TYPE: VARIABLE_SPEED
     ...
     CURVES:
       - SPEED: <shaft speed for this curve, a number>
         RATE: <list of rate values for this chart curve>
         HEAD: <list of polytropic head values for this chart curve>
         EFFICIENCY: <list of polytropic efficiency values for this chart curve>
+      - SPEED: <shaft speed for this curve, a number>
+        RATE: <list of rate values for this chart curve>
+        HEAD: <list of polytropic head values for this chart curve>
+        EFFICIENCY: <list of polytropic efficiency values for this chart curve>
 
   - NAME: <name of chart, for reference>
     TYPE: COMPRESSOR_CHART
+    CHART_TYPE: VARIABLE_SPEED
     ... 
     CURVES:
        - FILE: <filepath to compressor curve>
@@ -30,18 +35,23 @@ MODELS:
 
 ~~~~yaml
 MODELS:
-  - NAME: predefined_single_speed_compressor_chart
+  - NAME: predefined_variable_speed_compressor_chart
     TYPE: COMPRESSOR_CHART
-    CHART_TYPE: SINGLE_SPEED
+    CHART_TYPE: VARIABLE_SPEED
     ...
-    CURVE:
+    CURVES:
       - SPEED: 7500
         RATE: [2900, 3503, 4002, 4595.0]
         HEAD: [8412.9, 7996, 7363, 6127]
         EFFICIENCY: [0.72, 0.75, 0.74, 0.70]
+      - SPEED: 9886
+        RATE: [3708, 4502, 4993.6, 5507, 5924]
+        HEAD: [13845, 13182, 12425, 11276, 10054]
+        EFFICIENCY: [ 0.72, 0.75, 0.748, 0.73, 0.70]
 
   - NAME: compressor_chart
     TYPE: COMPRESSOR_CHART
+    CHART_TYPE: VARIABLE_SPEED
     ... 
     CURVES:
        - FILE: compressor_chart.csv