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adding contributor to notes

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This commit is contained in:
Sam Hatchett
2019-12-09 09:56:50 -05:00
parent c0fe89ceb5
commit 6639ce9b3e
1 changed files with 16 additions and 16 deletions
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ReleaseNotes2_2.md
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@@ -12,7 +12,7 @@ one would use:
`EN_getnodevalue(ph, nodeIndex, EN_ELEVATION, &elev)`
where `ph` is the handle assigned to the project.
where `ph` is the handle assigned to the project.
Two new functions have been added to the API to manage the creation and deletion of project handles. `EN_createproject` creates a new project along with its handle, while `EN_deleteproject` deletes a project. An example of using the thread-safe version of the API is shown below:
```
@@ -47,32 +47,32 @@ int buildandrunEpanet(char *rptfile)
err = EN_createproject(&ph);
if (err) return err;
EN_init(ph, rptfile, "", EN_GPM, EN_HW);
//Add a junction node with 710 ft elevation and 500 gpm demand
EN_addnode(ph, "J1", EN_JUNCTION, &index);
EN_setjuncdata(ph, index, 710, 500, "");
// Add a reservoir node at 800 ft elevation
EN_addnode(ph, "R1", EN_RESERVOIR, &index);
EN_setnodevalue(ph, index, EN_ELEVATION, 800);
// Add a 5280 ft long, 14-inch pipe with C-factor of 100
// from the reservoir to the demand node
EN_addlink(ph, "P1", EN_PIPE, "R1", "J1", &index);
EN_setpipedata(ph, index, 5280, 14, 100, 0);
// Solve for hydraulics and report nodal results
EN_setreport(ph, "NODES ALL");
err = EN_solveH(ph);
if (!err) err = EN_report(ph);
// Close and delete the project
EN_close(ph);
EN_deleteproject(ph);
return err;
}
```
Instead of using `EN_open` to load data from a file, `EN_init` is used to initialize a project with the names of its report and binary files, and its flow units and head loss formula. The legacy-style API has a complementary set of functions for building networks from code.
Instead of using `EN_open` to load data from a file, `EN_init` is used to initialize a project with the names of its report and binary files, and its flow units and head loss formula. The legacy-style API has a complementary set of functions for building networks from code.
## Additional Convergence Parameters
@@ -82,13 +82,13 @@ Two new analysis options have been added to provide more rigorous convergence cr
`EN_FLOWCHANGE` is the largest change in flow that any network element (link, emitter, or pressure-dependent demand) can have for hydraulic convergence to occur. It is specified in whatever flow units the project is using. The default value of 0 indicates that no flow change limit applies.
These new parameters augment the current `EN_ACCURACY` option which always remains in effect. In addition, both `EN_HEADERROR` and `EN_FLOWCHANGE` can be used as parameters in the `EN_getstatistic` (or `ENgetstatistic`) function to retrieve their computed values (even when their option values are 0) after a hydraulic solution has been completed.
These new parameters augment the current `EN_ACCURACY` option which always remains in effect. In addition, both `EN_HEADERROR` and `EN_FLOWCHANGE` can be used as parameters in the `EN_getstatistic` (or `ENgetstatistic`) function to retrieve their computed values (even when their option values are 0) after a hydraulic solution has been completed.
## More Efficient Node Re-ordering
EPANET's hydraulic solver requires solving a system of linear equations over a series of iterations until a set of convergence criteria are met. The coefficient matrix of this linear system is square and symmetric. It has a row for each network node and a non-zero off-diagonal coefficient for each link. The numerical effort needed to solve the linear system can be reduced if the nodes are re-ordered so that the non-zero coefficients cluster more tightly around the diagonal.
EPANET's original node re-ordering scheme has been replaced by the more efficient **Multiple Minimum Degree (MMD)** algorithm. On a series of eight networks ranging in size from 7,700 to 100,000 nodes MMD reduced the solution time for a single period (steady state) hydraulic analysis, where most of the work is for node-reordering, by an average of 55%. Since MMD did not reduce the time needed to solve the linear equations generated at each iteration of the hydraulic solver longer extended period simulations will not exhibit a similar speedup.
EPANET's original node re-ordering scheme has been replaced by the more efficient **Multiple Minimum Degree (MMD)** algorithm. On a series of eight networks ranging in size from 7,700 to 100,000 nodes MMD reduced the solution time for a single period (steady state) hydraulic analysis, where most of the work is for node-reordering, by an average of 55%. Since MMD did not reduce the time needed to solve the linear equations generated at each iteration of the hydraulic solver longer extended period simulations will not exhibit a similar speedup.
## Improved Handling of Near-Zero Flows
@@ -98,7 +98,7 @@ The hydraulic solver has been modified to use a linear head loss v. flow relatio
## Pressure Dependent Demands
EPANET has always employed a Demand Driven Analysis (**DDA**) when modeling network hydraulics. Under this approach nodal demands at a given point in time are fixed values that must be delivered no matter what nodal heads and link flows are produced by a hydraulic solution. This can result in situations where required demands are satisfied at nodes that have negative pressures - a physical impossibility.
EPANET has always employed a Demand Driven Analysis (**DDA**) when modeling network hydraulics. Under this approach nodal demands at a given point in time are fixed values that must be delivered no matter what nodal heads and link flows are produced by a hydraulic solution. This can result in situations where required demands are satisfied at nodes that have negative pressures - a physical impossibility.
To address this issue EPANET has been extended to use a Pressure Driven Analysis (**PDA**) if so desired. Under **PDA**, the demand D delivered at a node depends on the node's available pressure P according to:
@@ -165,7 +165,7 @@ With this change EPANET 2.2 now produces perfect mass balances when tested again
|`EN_deleterule`|Deletes a rule-based control from the project|
|`EN_setnodeid`|Changes the ID name for a node|
|`EN_setjuncdata` |Sets values for a junction's parameters |
|`EN_settankdata` |Sets values for a tank's parameters|
|`EN_settankdata` |Sets values for a tank's parameters|
|`EN_setlinkid`|Changes the ID name for a link|
|`EN_setlinknodes`|Sets a link's start- and end-nodes|
|`EN_setlinktype`|Changes the type of a specific link|
@@ -212,7 +212,7 @@ In addition to these new functions, a tank's volume curve `EN_VOLCURVE` can be s
- `EN_PUMP_ECOST` (average energy price)
- `EN_PUMP_EPAT` (energy pricing pattern)
- `EN_LINKPATTERN` (speed setting pattern)
Access to the following global energy options have been added to `EN_getoption` and `EN_setoption`:
- `EN_GLOBALEFFIC` (global pump efficiency)
- `EN_GLOBALPRICE` (global average energy price per kW-Hour)
@@ -262,7 +262,7 @@ Access to the following global energy options have been added to `EN_getoption`
- `EN_WALLORDER`
- `EN_TANKORDER`
- `EN_CONCENLIMIT`
### Simulation statistic types:
- `EN_MAXHEADERROR`
- `EN_MAXFLOWCHANGE`
@@ -286,8 +286,8 @@ Access to the following global energy options have been added to `EN_getoption`
- `EN_PDA`
## Documentation
Doxygen files have been created to generate a complete Users Guide for version 2.2's API. The guide's format is similar to the original EPANET Programmer's Toolkit help file and can be produced as a set of HTML pages, a Windows help file or a PDF document.
Doxygen files have been created to generate a complete Users Guide for version 2.2's API. The guide's format is similar to the original EPANET Programmer's Toolkit help file and can be produced as a set of HTML pages, a Windows help file or a PDF document.
## Authors contributing to this release:
(In alphabetical order)
- Demetrios Eliades
@@ -295,5 +295,5 @@ Doxygen files have been created to generate a complete Users Guide for version 2
- Marios Kyriakou
- Lewis Rossman
- Elad Salomons
- Markus Sunela
- Michael Tryby