Bentley HAMMER Theory and Practice
Bentley HAMMER CONNECT is an advanced numerical simulator of hydraulic transient phenomena (water hammer) in water, wastewater, industrial, and mining systems. Built with busy engineers in mind, it simplifies data entry and allows you to focus on visualizing, improving, and delivering your results quickly and professionally. Bentley HAMMER CONNECT can handle any fluid or system that a typical steady-state hydraulic model like WaterCAD can, but it can also solve a broader range of problems, as shown in the table below.
Table 14-1: Bentley HAMMER CONNECT Capabilities
| WaterCAD | Bentley HAMMER CONNECT* |
| Steady or gradually varying turbulent flow | Rapidly varying or transient flow |
| Incompressible, Newtonian, single-phase fluids | Slightly compressible, two-phase fluids (vapor and liquid) and two-fluid systems (air and liquid) |
| Full pipes | Closed-conduit pressurized systems with air intake and release at discrete points |
Bentley HAMMER CONNECT capabilities are in addition to WaterCAD's capabilities
With Bentley HAMMER CONNECT, you can analyze drinking water systems, sewage forcemains, fire protection systems, well pumps, and raw-water transmission lines. You can change the specific gravity of the fluid to model oil or slurries, for example. Bentley HAMMER CONNECT assumes that changes in other fluid properties, such as temperature, are negligible. It does not currently model fluids with significant thermal variations, such as can occur in cogeneration or industrial systems.
The Bentley HAMMER CONNECT algorithms will grow and evolve to keep pace with the state of the practice in water distribution and wastewater collection modeling. Because the mathematical solution methods are continually extended, this manual deals primarily with the fundamental principles underlying these algorithms and focuses less on the details of their implementation.
This appendix introduces the principles of hydraulic transients in piping systems, reviews current analytical approaches and engineering practices, discusses the potential sources and impacts of water hammer, and presents a proven approach to help you select and size surge-control equipment. Several transient simulations are integrated into the discussion to provide context.