The program HYKAS performs the hydraulic computation of sewer networks as according to the DWA A 118 guidelines. Apart from transient hydrodynamic computations, two steady state calculation methods (time coefficients and the storage indication method) are also put forth. The rainfall intensity can be determined either using Reinhold or KOSTRA (the KOSTRA DVD 2000 includes a variety of iteration methods published in the past). Standard MS ACCESS is used for database.
Unsteady-State condition
Basics of design
The program follows the guidelines recommended by DWA A 110.
Sewer networks can be user-defined for combined, storm or waste water systems.
Automatic generation of Euler rainfall curve model (Type II) from the DWD's KOSTRA data set possible.
Determination of overtopping frequency using rainfall curves model, heavy rainfall series, or extreme events.
The hydraulic calculations are set to be performed for a free surface flow where the surface runoff is calculated either using an empirical approach of Keser or by the Boundary value method.
The actual hydraulic computation (Unsteady flow condition) is based upon the complete solution of the St Venant's equations. The solution methods explicitly or implicitly can be selected alternatively.
HYKAS also comes with a brand new and even faster implicit algorithm, called "implicit dynamic". It's based on the Storm Water Management Model, Version 5, designed by the U.S. Environmental Protection Agency. The algorithm was adapted to A 110 and A 118 guidelines.
Detaillierte Darstellung von Pumpenlaufzeiten durch Vorgabe volumen- bzw. wasserspiegelabhängige Schaltzeiten und druckhöhenabhängige oder wasserspiegelabhängige Kennlinien.
HYKAS ermöglicht die regelbasierte Kanalnetzberechnung, bei der die Simulation lokaler Steuerungseingriffe das Ziel ist.
Special structures are integrated into the calculations including their boundary conditions. Such structures are storm water overflow basins (weir overflow calculations using the Poleni formula), pumps, outfalls, lateral outfalls, and storage bays.
Am Schacht austretendes Wasser kann zwischengespeichert und in das Netz zurückgeführt werden, wenn es wieder aufnahmefähig ist. Diese Eigenschaft kann für jeden einzelnen Schacht des Netzes festgelegt werden.
Die Trockenwetterabflussberechnung bei Mischsystemen wird hydrodynamisch durchgeführt.
Im Berechnungsprotokoll werden neben der Volumenbilanz insbesondere die Schächte und Haltungen ausgewiesen, welche HYKAS während der Simulation als eventuell problematisch aufgefallen sind. Es erfolgen Hinweise auf zeitschrittkritische Elemente, max. Kontinuitätsfehler und Anzahl Fließrichtungsumkehr.
The implict dynamic algorithm usually only needs a few iterations in order to deliver a stable calculation result. This leads to a very high calculation speed. Even long simulation durations can be handled easily by this algorithm.
The user can define the individual roughness factor of a reach after DWA-Arbeitsblatt A110, Kapitel 4.
The discharge and stage hydrograph curves of each conduit are stored during the computation and can be evaluated afterwards.
The surface runoff of individual catchment areas can be classified in detail separately with the menu option.
HYKAS bietet eine hydrodynamische Langzeit-Kontinuum-Simulation an. Alle gängigen Regenformate (u.a. NTAPE, MD-Format) können verarbeitet werden. HYKAS führt eine Extremwertanalyse durch und liefert - auf einen beliebigen Zeitintervall bezogen - die Abflussmengen, die Max-Ergebnisse sowie Mittelwert und Standardabweichung. Zur grafischen Auswertung der Ergebnisse bringt HYKAS auch ein Analysewerkzeug mit.
During the collection of catchment areas, infiltration-relevant surface portions can be considered.
The column headings are fully editable. Default settings are applied initially.
While displaying the compilation result of conduit data, the option for format selection is made between a form or tabular type. Additionally, the user may also select from a wide variety of grouping, sorting, search, and filter functions.
Data output
The Output data lists are then provided as a preview on the monitor. At this stage, the user may choose to print the results, or save them on the clipboard for later use as RTF or HTML file formats.
The following output lists are created by the HYKAS unsteady calculations:
| • | Overview of the inputs for calculation |
| • | Detailed volume balance |
| • | Output results in a listed format |
| • | Statistical Analysis |
| • | List of the selected special construction types |
| • | Topology ID list |
| • | List of additional watersheds |
| • | Conduit lists sorted after setting a condition, design, as well as complete pipe list summary |
| • | Topology ID list |
| • | Additional catchments list |
| • | Pipe lists that can be sorted by status, a list with all pipes is available, too |
Application limitations per project
Implicit dynamic algorithm: No software-related bounds
Explicit+implicit algorithms:
| • | Max. | 10,000 | Conduits |
| • | Max. | 500 | Topology IDs |
| • | Max. | 200 | Single rules |
| • | Max. | 100 | Profile shapes |
| • | Max. | 10,000 | Water surface elevations and Discharge curves |
| • | Unlimited | Free Outfalls, Weir, Pumps, Sumps, Outfalls, Lateral Outfalls, Inflow Hydrograph |
Pollution management
HYKAS ermöglicht Ihnen auch eine Schmutzfrachtsimulation. Wenn bei der Erfassung der Einzugsgebiete die Schmutzfrachten d.h. deren Auf- und Abbau und durch Festlegen der Landnutzung definiert werden, liefert HYKAS auf der Grundlage der hydrodynamischen Kanalnetzberechnung bzw. der hydrodynamischen Langzeit-Kontinuum-Simulation die Schmutzfrachten im Kanalnetz.
Es ist damit gewährleistet, dass bei der Ermittlung der Ableitung von Schmutzfrachten in den Vorfluter Translations- und Retentionseffekte, die im Kanalnetz auftreten, berücksichtigt werden.
Steady-State calculations
Two steady state sewer network models Time Factor- and Summation curve Method are available. The user can use these methods for creating new designs, or to ascertain the performance of existing systems for combination, storm water, and sewer canals, creating a water balance report as well as a calculation of the backwater curve. The rain intensity can be determined using either KOSTRA or Reinhold.
Note: There is an additional Swiss version of HYKAS which makes use of the Swiss Hörler/Rhein time coefficients instead of using the German methods. The basic functional forms of both versions are however identical. In beginning the hydraulic calculations, the location coefficient K and location constant B must be input when using the Hörler/Rhein method to determine the controlling rainfall intensity.
Basics of design
The program follows the guidelines of DWA A 110.
Sewer networks can be user-defined as combined, storm or waste water systems.
The Hydraulic calculations are performed according to the Prandl-Colebrook formulation.
For steep-slope conduits, the effects of air entrainment are considered. Affected conduits are indicated accordingly in the printout.
For the new design of the conduit inlet, the user may choose either crown, axial or bottom wise.
Tables showing the existing profiles are as per DWA A 110. Additional table can be generated either explicity or created by the program using the profile coordinates. The curves are then displayed on the monitor and can be printed.
The rate of rainfall can be selected as according to Reinhold or any of the four methods of KOSTRA before running the hydraulic calculations.
For the description of storm water overflow structures, both the crest height and the overflow head can be described. The effects of the overflow head on the backwater curve are considered in the hydraulic calculations. Additionally, the program calculates the controlling storage volume between the water surface during low flow conditions and water till the crestlevel.
The water balance in branched networks is iteratively calculated along the flow direction.
The program determines the flow condition (subcritical or supercritical) and indicates the conduits if having supercritical flow condition in the printout.
Conduits with reverse gradients or horizontal can also be considered in running the hydraulic calculations.
Data output
The following lists are created by the HYKAS unsteady calculations: (the column headings can be changed by the user with respect to content and type)
| • | List showing the calculation results |
| • | List of storm water overflows |
| • | Topology ID list |
| • | List of the additional watersheds |
| • | Conduit lists (condition and design) |
Application limitations per project
| • | Max. | 10,000 | Conduits |
| • | Max. | 500 | Topology IDs |
| • | Max. | 100 | Profile shapes |
Data exchange
The following REHM programs use the same data types as HYKAS:
| KAREL | Channel information system |
| GraPS | Graphical planning system for Sewer and Water Supply nets |
| KANALPLOT | Drawing of Channel profiles |
| MENKOS | Quantity and Cost estimation |
| WERT | Property valuation for Sewage Network |
The following user interfaces are additionally offered:
| ISYBAU (Format 96) | The following ISYBAU formats are available for import and export: KE, Y |
| ISYBAU XML 2006 | See the user interface LisyTrans |
| ASCII interface | The required data formats for both importing and exporting data can be freely defined. |