Read "How To Simulate Tapes Using Spraylines" first.
Due to the size constraints in IRRICAD it is sometimes useful to be able to reduce the size of an analysis by combining a number of laterals / driplines into a single notional one. This is especially true in highly looped systems such as the analysis of tape / lateral blocks with flushing submains. The following notes show how to accomplish this.
Add a new emitter / emitter nozzle to the database that has the same index as one used on the single lateral / dripline. The constant will be n times the single one, where n is the number of laterals being combined. If you are using a tape / dripline then see the notes on flushing analysis for sources of the emitter equation. Make sure that the warehouse code is different to the normal emitter / nozzle.
A new pipe needs to be added to mirror the hydraulic performance of the required number of laterals / driplines. Make sure that the description identifies what the pipe is for and use a unique warehouse code. The actual diameter is set by the following equation:
Due to the size constraints in IRRICAD it is sometimes useful to be able to reduce the size of an analysis by combining a number of laterals / driplines into a single notional one. This is especially true in highly looped systems such as the analysis of tape / lateral blocks with flushing submains. The following notes show how to accomplish this.
Add a new emitter / emitter nozzle to the database that has the same index as one used on the single lateral / dripline. The constant will be n times the single one, where n is the number of laterals being combined. If you are using a tape / dripline then see the notes on flushing analysis for sources of the emitter equation. Make sure that the warehouse code is different to the normal emitter / nozzle.
A new pipe needs to be added to mirror the hydraulic performance of the required number of laterals / driplines. Make sure that the description identifies what the pipe is for and use a unique warehouse code. The actual diameter is set by the following equation:
Dnew = (d4.871 x n1.852)0.2053
where d is the single lateral diameter, n is the number of laterals being combined, and Dnew is the diameter of the combined lateral. For example a 16mm ID combined into 10 laterals gives a new diameter of 38.4mm. This equation will work with any units. Use the same C factor as for the single lateral.
Make a copy of your design and remove the laterals that are going to be combined leaving one for each group. Generally it is best to have the notional lateral approximately in the center of the group of laterals being modeled. This means that you will need a half lateral at the beginning and end of the submain, the diameter and emitter parameters for this lateral will need to be calculated and entered into the database separately. For example if you have 100 laterals that you are splitting up into groups of 10 then you should start and end with a group of 5 and then have 9 groups of 10 laterals in between. Change tapes to spraylines if required and then replace the emitters and pipes with the Multiple items determined above.
SUMMARY
Make a copy of your design and remove the laterals that are going to be combined leaving one for each group. Generally it is best to have the notional lateral approximately in the center of the group of laterals being modeled. This means that you will need a half lateral at the beginning and end of the submain, the diameter and emitter parameters for this lateral will need to be calculated and entered into the database separately. For example if you have 100 laterals that you are splitting up into groups of 10 then you should start and end with a group of 5 and then have 9 groups of 10 laterals in between. Change tapes to spraylines if required and then replace the emitters and pipes with the Multiple items determined above.
SUMMARY
- Create an outlet and nozzle to simulate the multiple laterals.
- Create a new pipe.
- Remove a group of laterals and replace with a single lateral.