# WORKSHOP 13 A SPRINKLER SYSTEM HYDRAULIC ANALYSIS

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WORKSHOP 13 A SPRINKLER SYSTEM HYDRAULIC ANALYSIS

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Model Description In this exercise you will create schematic geometry which models a sprinkler system for a medium size lawn. The model is a schematic since the actual pipe lengths in the circuit will be defined via the Element Properties from. All fitting losses have been included as additions to pipe lengths. The home for which this sprinkler is designed can comfortably deliver 12 gallons per minute (GPM) of water at 42 psi through the existing main. Since both the volumetric flow through and the coverage from each sprinkler head are a function of pressure at the head, this analysis will determine whether the pressure at each head is above 30 psi and whether the entry volumetric flow demand is less that 12 GPM. All data provided yield an analysis in English Engineering units, lbf, lbm, s, feet. However here are some useful conversion factors for evaluating the results: 1 cu. Ft. = 7.481 gal. And 1 sq. ft. = 144 sq. in.

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Exercise Overview Create a new database named exercise_13.db. Set Tolerance to Default, and the Analysis Code to MSC/THERMAL. Create flow network schematic geometry using the Geometry form Create and Transform Actions. Create FEM entities. Create nodes matching geometric points and mesh curve with BAR2 elements. Equivalence nodes. Define element properties for 1D Flow network bar elements using IOPT=2 for automatic friction factor calculation. Use Utilities/Thermal/Hydraulic Icon to check flow direction. Create three NonSpatial/General fields which define the sprinkler head volumetric flow as a function of pressure. Define inlet pressure and sprinkler head mass flow conditions. Use Analysis/Build Template to create the template.dat.apnd file. Select Analysis to prepare and to submit the model for analysis and to Read Results. Run the analysis and read the results into the database. Quit MSC/PATRAN. Objectives Model a schematic of a home sprinkler system. Use microfunctions to apply pressure varying mass flow functions at the sprinkler heads. Run a hydraulic analysis to evaluate the pressure drop and total mass flow through the system.

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Step 1: Create a New Database Create a new database called exercise_13.db. File / New. Enter exercise_13 as the file name. Click OK. Choose Default Tolerance. Select MSC.Thermal as the Analysis Code. Select Thermal as the Analysis Type. OK. a b c d e f g

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Step 2: Create Network Schematic Geometry Create flow network schematic geometry. Turn on labels using the following icon. Increase the size of the Point markers using Display: Geometry/Point Size: 4. Geometry. Set to Create/Point/XYZ. Enter [0 6 0] for Point Coordinates List. Apply. Enter [6 0 0] for Point Coordinates List. Apply. Enter [6 12 0] for Point Coordinates List. Apply. a d e f b c

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Step 2: Create Network Schematic Geometry (Cont.) Translate points using the following Action, object and Method. Transform/Point/Translate. Deselect Auto Execute. Enter <6 0 0 > for Translation Vector. Enter 5 for Repeat Count. Select Point 1 for Point List. Apply. Enter <12 0 0> for Translation Vector. Enter 2 for Repeat Count. Enter Point 2 3 for Point List. Apply. Enter <0 3 0> for Translation Vector. Enter 1 for Repeat Count. Enter Point 5 7 for Point List. Apply.

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Step 2: Create Network Schematic Geometry (Cont.)

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Step 2: Create Network Schematic Geometry (Cont.) Create curves using the following Action, Object, and Method. Create/Curve/Point. Enter Point 1 for Starting Point List. Enter Point 4 for Ending Point List. Apply. Repeat these steps using the starting and ending points from the following table. a b c d

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Step 2: Create Network Schematic Geometry (Cont.)

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Step 3: Create Nodes and Elements Create FEM entities on the curves. First, create nodes at geometric points. This is so Node “j” will be coincident with Point “j”. Then, subsequent meshing and equivalencing will produce Bar2 elements with node numbers that match the point numbers. Finite Elements. Create/Node/Edit. Click in Node Location List and drag a rectangle around all the geometry in the viewport, Point 1:14. Apply. a b c d Nodes at Points Points at Vertices

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b c d e Continue creating FEM entities. Mesh curves with Bar2 elements. Finite Elements. Set to Create/Mesh/Curve. Enter 12.0 for Global Edge Length (deselect Automatic Calculation). Click in Curve List and select all curves in the viewport, Curve 1:13. Apply. Step 3: Create Nodes and Elements (Cont.) a

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Step 4: Equivalence Nodes Equivalence nodes to connect Bar2 elements. Finite Elements. Equivalence/All/ Tolerance Cube. Apply. a b c

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Step 5: Create 1D Flow Elements Define element properties for 1D Flow network bar elements. Properties. Set to Create/1D/Flow network bar. Enter Entry for Property Set Name. Click Input Properties… Enter 1 for [TID]. Enter 2 for IOPT. Enter 0.0625 for [Pipe diameter]. Enter 50.00 for [Pipe Length]. Enter 0.0 for [Pipe roughness]. Enter 62.46 for [Fluid density]. Enter 6.764e-4 for [Fluid viscosity]. OK. Click in Select Members box and select Curve 1. Add. Apply. Repeat for the following set listed in the table. Values that are not listed should stay untouched (left the same). a b c d l m o p n

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Step 6: Verify Flow Directions Use Utilities: Thermal/Hydraulic Icon to verify flow directions. Utilities. Select Thermal. Select Hydraulic Icon… Click OK if the disclaimer appears. Apply. Clear. Close. a b c e f g

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Step 7: Create Micro-Functions/Fields Create first NonSpatial fields which defines the sprinkler head volumetric flow as a function of pressure. Fields. Create/Non Spatial/General. Enter Full_GPM for Field Name. Click Input Data… Select mfid_indx_linr_tabl for Select Function Term. Enter 1100 for Micro Function ID (MFID). Enter Full_GPM for Field MFID Description. Select Temperature for Independent Variable Type. Enter 0.0 for Input: Temperature (X). Enter 0.0 for Input: Value, Function (X). Enter 2880.0 for Input: Temperature (X). Enter 1.67 for Input: Value, Function (X). Enter 4320.0 for Input: Temperature (X). Enter 2.19 for Input: Value, Function (X). Enter 5760.0 for Input: Temperature (X). Enter 2.35 for Input: Value, Function (X). Enter 7200.0 for Input: Temperature (X). Enter 2.7 for Input: Value, Function (X). Click OK, OK and Apply. a b c d f h s g

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Create second NonSpatial fields which defines the sprinkler head volumetric flow as a function of pressure. Enter Half_GPM for Field Name. Click Input Data… Select mfid_indx_linr_tabl for Select Function Term. Select Defaults to clear the form. Enter 1050 for Micro Function ID (MFID). Enter Half_GPM for Field MFID Description. Select Temperature for Independent Variable Type. Enter 0.0 for Input: Temperature (X). Enter 0.0 for Input: Value, Function (X). Enter 2880.0 for Input: Temperature (X). Enter 0.95 for Input: Value, Function (X). Enter 4320.0 for Input: Temperature (X). Enter 1.09 for Input: Value, Function (X). Enter 5760.0 for Input: Temperature (X). Enter 1.3 for Input: Value, Function (X). Enter 7200.0 for Input: Temperature (X). Enter 1.55 Input: Value, Function (X). Click OK, OK, then Apply. a b e f q d g h r Step 7: Create Micro-Functions/Fields (Cont.)

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Create third NonSpatial fields which defines the sprinkler head volumetric flow as a function of pressure. Enter Quarter_GPM for Field Name. Click Input Data… Select mfid_indx_linr_tabl for Select Function Term. Click Defaults. Enter 1025 for Micro Function ID (MFID). Enter Quarter_GPM for Field MFID Description. Select Temperature for Independent Variable Type. Enter 0.0 for Input: Temperature (X). Enter 0.0 for Input: Value, Function (X). Enter 2880.0 for Input: Temperature (X). Enter 0.40 for Input: Value, Function (X). Enter 4320.0 for Input: Temperature (X). Enter 0.50 for Input: Value, Function (X). Enter 5760.0 for Input: Temperature (X). Enter 0.60 for Input: Value, Function (X). Enter 7200.0 for Input: Temperature (X). Enter 0.63 for Input: Value, Function (X). Click OK, OK, then Apply. e b a f q d g h r Step 7: Create Micro-Functions/Fields (Cont.)

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Step 8: Apply Boundary Conditions Define inlet pressure and sprinkler head mass flow conditions. Loads/BCs. Create/Pressure/Nodal. Select Fixed for Option. Enter Entry as New Set Name. Click Input Data… Enter 6048 for Fixed Pressure. OK. Click Select Application Region… Select Point 1 for Select Geometry Entities. Add. OK. Apply. a b c d e f g h i k l j

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Step 8: Apply Boundary Conditions (Cont.) Create a variable mass flow rate. Loads/BCs. Create/Mass Flow Rate/Nodal. Select Template for Option. Enter Full for New Set Name. Click Input Data… Enter 1.0 for Mass Flow Rate Multiplier. Enter 100 for Template ID. OK. Select Application Region… Select Points 13 and 14 for Select Geometry Entities. Add. OK. Apply. a b c d e f g h i j l m k

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Step 8: Apply Boundary Conditions (Cont.) Repeat these steps for another two locations/points. Enter Half for New Set Name. Input Data… Enter 1.0 for Mass Flow Rate Multiplier. Enter 50 for Template ID. OK. Select Application Region… Select Points 9 and 10 for Select Geometry Entities. Add. OK. Apply. a b c d e f g i j h

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Step 8: Apply Boundary Conditions (Cont.) Repeat these steps for four more locations/points. Enter Quarter for New Set Name. Input Data… Enter 1.0 for Mass Flow Rate Multiplier. Enter 25 for Template ID. OK. Select Application Region… Select Points 2, 3, 11, and 12 for Select Geometry Entities. Add. OK. Apply. a b c d e f g i j h

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Step 8: Apply Boundary Conditions (Cont.) Change the view. Change to the isometric view using the following icon. Hide the point, curve, and node labels, and display the element labels. a b

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Step 9: Create template.dat.apnd File Use Analysis: Build Template to create the file template.dat.apnd file. Analysis. Build template. Click Create Template File… Create/MACRO/Data Entry. Enter 25 for MACRO ID. Enter 1025 for MFID’s. Enter –0.139 for Scale Factor. Apply. Click Cancel in Template Entries form. Repeat these steps with the information in the table. After entering the last set of information do not cancel Template Entries form, but select Write File… In the box for File name input template.dat.apnd. OK. Cancel. Cancel. a

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Step 9: Create template.dat.apnd File (Cont.) Contents of template.dat.apnd file.

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Step 10: Prepare and Run Analysis Prepare and submit the model for analysis. Analysis. Analyze/Full Model/Full Run. Click Solution Type… Select Perform Hydraulic Analysis. OK. Click Solution Parameters… Select Fahrenheit for Calculation Temperature Scale. OK. Click Output Requests… Select Fahrenheit for Units Scale for Output Temperatures. Deselect Temperatures Click Nodal Results File Format…, and select all hydraulic node and element entries to output. OK. OK. Apply. a b c d f g l m o i k

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Step 11: Read and Plot Results Read results via the Analysis form. Analysis. Read Result/Result Entities. Click Select Results File… Under directories select the path that will lead to exerices_13. Select np0.nrf.01 for available files. OK. Click Select Rslt Template File… Select pthermal_1_pnodal.res_tmpl for File name. OK. Apply. a b c d f g h i j e

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Step 11: Read and Plot Results (Cont.) Display the pressure results on the model. Results. Create/Quick Plot. Select HYDRAULIC TIME … under Select Result Cases. Select Pressure under Select Fringe Result. Click on Fringe Attributes icon. Select a wider line to display the results on. Select to not display the title. Click on Apply, and see results. Create and use a Range. b i e c g f d a

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Step 11: Read and Plot Results (Cont.) Display the pressure results on the model. Create and use a range. (continued) Click on Create. Enter pressure under New Range Name. Enter 12 under Number of Sub-Ranges. Click OK. Click on Fit Results. Click on Calculate. Click on Apply. Click on Assign Target Range to Viewport. a b c d e f h

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Step 11: Read and Plot Results (Cont.)

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Step 12: Quit MSC.Patran Quit MSC.Patran. Select File. Click Quit from the drop down menu.

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