Merge pull request #8040 from bigladder/fix-siteprecipitation-largeou…

…tputs

Fix Site:Precipitation divide-by-zero

src/EnergyPlus/WaterManager.cc

@@ -1000,7 +1000,11 @@ namespace WaterManager {
 
         if (RainFall.ModeID == RainSchedDesign) {
             schedRate = GetCurrentScheduleValue(RainFall.RainSchedID); // m/hr
-            ScaleFactor = RainFall.DesignAnnualRain / RainFall.NomAnnualRain;
+            if (RainFall.NomAnnualRain > 0.0){
+                ScaleFactor = RainFall.DesignAnnualRain / RainFall.NomAnnualRain;
+            } else {
+                ScaleFactor = 0.0;
+            }
             RainFall.CurrentRate = schedRate * ScaleFactor / SecInHour; // convert to m/s
             RainFall.CurrentAmount = RainFall.CurrentRate * (TimeStepSys * SecInHour);
         }

tst/EnergyPlus/unit/CMakeLists.txt

@@ -191,6 +191,7 @@ set( test_src
   Vector.unit.cc
   VentilatedSlab.unit.cc
   WaterCoils.unit.cc
+  WaterManager.unit.cc
   WaterThermalTanks.unit.cc
   WaterToAirHeatPump.unit.cc
   WaterToAirHeatPumpSimple.unit.cc

tst/EnergyPlus/unit/WaterManager.unit.cc

@@ -0,0 +1,123 @@
+// EnergyPlus, Copyright (c) 1996-2020, The Board of Trustees of the University of Illinois,
+// The Regents of the University of California, through Lawrence Berkeley National Laboratory
+// (subject to receipt of any required approvals from the U.S. Dept. of Energy), Oak Ridge
+// National Laboratory, managed by UT-Battelle, Alliance for Sustainable Energy, LLC, and other
+// contributors. All rights reserved.
+//
+// NOTICE: This Software was developed under funding from the U.S. Department of Energy and the
+// U.S. Government consequently retains certain rights. As such, the U.S. Government has been
+// granted for itself and others acting on its behalf a paid-up, nonexclusive, irrevocable,
+// worldwide license in the Software to reproduce, distribute copies to the public, prepare
+// derivative works, and perform publicly and display publicly, and to permit others to do so.
+//
+// Redistribution and use in source and binary forms, with or without modification, are permitted
+// provided that the following conditions are met:
+//
+// (1) Redistributions of source code must retain the above copyright notice, this list of
+//     conditions and the following disclaimer.
+//
+// (2) Redistributions in binary form must reproduce the above copyright notice, this list of
+//     conditions and the following disclaimer in the documentation and/or other materials
+//     provided with the distribution.
+//
+// (3) Neither the name of the University of California, Lawrence Berkeley National Laboratory,
+//     the University of Illinois, U.S. Dept. of Energy nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without specific prior
+//     written permission.
+//
+// (4) Use of EnergyPlus(TM) Name. If Licensee (i) distributes the software in stand-alone form
+//     without changes from the version obtained under this License, or (ii) Licensee makes a
+//     reference solely to the software portion of its product, Licensee must refer to the
+//     software as "EnergyPlus version X" software, where "X" is the version number Licensee
+//     obtained under this License and may not use a different name for the software. Except as
+//     specifically required in this Section (4), Licensee shall not use in a company name, a
+//     product name, in advertising, publicity, or other promotional activities any name, trade
+//     name, trademark, logo, or other designation of "EnergyPlus", "E+", "e+" or confusingly
+//     similar designation, without the U.S. Department of Energy's prior written consent.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+
+// Google Test Headers
+#include <gtest/gtest.h>
+
+// EnergyPlus Headers
+#include <EnergyPlus/WaterManager.hh>
+#include <EnergyPlus/DataWater.hh>
+#include <EnergyPlus/ScheduleManager.hh>
+
+#include "Fixtures/EnergyPlusFixture.hh"
+
+
+using namespace EnergyPlus;
+
+TEST_F(EnergyPlusFixture, WaterManager_NormalAnnualPrecipitation)
+{
+    // This unit test ensures that the WaterManager correctly calculates the Rainfall CurrentRate
+    std::string const idf_objects = delimited_string({
+        "Site:Precipitation,",
+        "ScheduleAndDesignLevel,  !- Precipitation Model Type",
+        "0.75,                    !- Design Level for Total Annual Precipitation {m/yr}",
+        "PrecipitationSchd,       !- Precipitation Rates Schedule Name",
+        "0.80771;                 !- Average Total Annual Precipitation {m/yr}",
+
+        "Schedule:Constant,",
+        "PrecipitationSchd,",
+        ",",
+        "1;",
+    });
+    ASSERT_TRUE(process_idf(idf_objects));
+
+    WaterManager::GetWaterManagerInput();
+
+    ScheduleManager::Schedule(1).CurrentValue = 1.0;
+
+    WaterManager::UpdatePrecipitation();
+
+    Real64 ExpectedNomAnnualRain = 0.80771;
+    Real64 ExpectedCurrentRate = 1.0 * (0.75 / 0.80771) / DataGlobals::SecInHour;
+
+    Real64 NomAnnualRain = DataWater::RainFall.NomAnnualRain;
+    EXPECT_NEAR(NomAnnualRain, ExpectedNomAnnualRain, 0.000001);
+
+    Real64 CurrentRate = DataWater::RainFall.CurrentRate;
+    EXPECT_NEAR(CurrentRate, ExpectedCurrentRate, 0.000001);
+}
+
+TEST_F(EnergyPlusFixture, WaterManager_ZeroAnnualPrecipitation)
+{
+    // This unit test ensures that the WaterManager does not attempt a divide by zero error when
+    // the average total annual precipitation input is zero.
+    std::string const idf_objects = delimited_string({
+        "Site:Precipitation,",
+        "ScheduleAndDesignLevel,  !- Precipitation Model Type",
+        "0.75,                    !- Design Level for Total Annual Precipitation {m/yr}",
+        "PrecipitationSchd,       !- Precipitation Rates Schedule Name",
+        "0.0;                     !- Average Total Annual Precipitation {m/yr}",
+
+        "Schedule:Constant,",
+        "PrecipitationSchd,",
+        ",",
+        "1;",
+    });
+    ASSERT_TRUE(process_idf(idf_objects));
+    WaterManager::GetWaterManagerInput();
+
+    ScheduleManager::Schedule(1).CurrentValue = 1.0;
+
+    WaterManager::UpdatePrecipitation();
+
+    Real64 NomAnnualRain = DataWater::RainFall.NomAnnualRain;
+    EXPECT_NEAR(NomAnnualRain, 0.0, 0.000001);
+
+    Real64 CurrentRate = DataWater::RainFall.CurrentRate;
+    EXPECT_NEAR(CurrentRate, 0.0, 0.000001);
+}