InfoSurge is a surge engine (InfoSurge V10) that is able to simulate transient events caused by turbine operation, and Pressure Reducing Valve (PRV)/Flow Control Valve (FCV) responses to transients.
The primary InfoSurge user interface consists of the InfoSurge toolbar. For more information on InfoSurge's interface, refer to InfoSurge User Interface. This toolbar is added to the Model Explorer as shown below. Each InfoSurge tool has a specific function and will be made active when the proper element type is selected. Toolbar buttons that are grayed out do not apply to the selected element. The various toolbar buttons will become active as different element types are selected.
You can access the InfoSurge toolbar from the Model Explorer:
Introduction to InfoSurge
Pressure surges (waterhammer) in water distribution systems can cause many problems. These include failure of pumps, pipe ruptures, and the backflow of dirty water (pathogen intrusion) into the distribution system. Transients during pump startup and shutdown will stress the system leading to increased leakage and decreased reliability. Uncontrolled pump shutdown (downsurge) can lead to the undesirable occurrence of water-column separation, which can result in catastrophic pipeline failures due to severe pressure rises following the collapse of vapor cavity.
Transient flow simulation and analysis is an essential requirement for assuring the safety and safe operation of water distribution piping systems. InfoSurge is the result of an extended effort to develop a comprehensive modeling application, which can be readily used by engineers and scientists concerned with transient operation of pipe systems transporting liquids. Vapor cavitation and liquid column separation are explicitly modeled, allowing the effect of pressure surges due to vapor cavity collapse to be properly evaluated. The program is designed to rapidly and accurately compute pressures and flows throughout the piping system during transient operation and evaluate alternate operational scenarios and surge protection schemes.
Hydraulic transients describe the disturbances in a fluid caused during a change from one steady-state to another. The principle components of the disturbances are pressure changes caused by the propagation of pressure waves throughout the distribution system. These pressure waves continue to propagate with the velocity of sound until they are dissipated down to the level of the new steady-state by the action of some form of damping or friction. Only if the flow is regulated extremely slowly is it possible to undertake a smooth transition from one steady-state to another without large fluctuations in pressure head or pipe velocity.
Disturbances in water distribution systems can be induced by the following situations:
- Pump startup or shutdown
- Valve opening or closing (variation in flow area)
- Changes in boundary pressures (reservoir level, pressure tank, etc.)
- Rapid changes in demand conditions (e.g., hydrant flushing)
- Changes in transmission conditions (e.g., pipe break)
Potentially, these disturbances can create serious consequences for water utilities if not properly recognized and addressed by proper analysis and design considerations. Hydraulic systems must be designed to accommodate both normal and abnormal operations and safeguarded to handle adverse external events such as power failure, pipeline fracture, etc. The main design considerations generally used to mitigate transient conditions are: (1) alteration of pipeline characteristics (e.g., pipe diameter); (2) improvement in valve and pump control procedures; and (3) design and installation of surge protection devices. A number of devices which are employed to control pressure and flow transients can be modeled by InfoSurge. These include:
- Open surge tanks
- Closed surge vessels
- Bladder tanks
- Hybrid tanks (vented to admit air)
- Bypass lines
- Check valves
- Feed tanks (provide inflow to prevent cavitation)
- Air release/vacuum valves (2 and 3 stage valves)
- Pressure relief valves
- Surge anticipation valves
InfoSurge lets you quickly view your water distribution system's response to pump station power failures, valve closures, and pump speed changes, and identify special protection measures to reduce pipe leaks, avoid breaks, investigate control actions and strategies, and improve water quality in your distribution system. InfoSurge is an invaluable tool for assessing the response of systems to changes in surge protection devices and their characteristics. It can be effectively used to evaluate the relative merits and shortcomings of each protection device. Usually the best solution is a combination of several devices.
InfoSurge solves the basic conservational equations of fluid mechanics for the transient flow of an incompressible fluid in a pipe network. The powerful and highly efficient “wave characteristic method” is used, which combines the good convergence properties of Lagrangian-type methods (e.g., wave plan method) and the better explicit formulation of distributed friction effects and inherent accuracy of Eulerian-type methods (e.g., method of characteristics). The method produces essentially the same results as the method of characteristics, which compare favorably to exact analytical solutions. The wave characteristic method is Lagrangian in nature and is based on tracking the movement and magnitude of pressure waves as they move along pipes and get transmitted and reflected at the junctions between fixed-length time steps. Pressure and flow time histories are computed for any point in the network by summing with time the contributions of incremental waves. Friction effects are explicitly considered in a distributed manner. The method is conceptually simple and provides the engineer valuable insights into the transient behavior of their systems. In addition, for larger systems, the wave characteristic method requires far fewer computational efforts than Eulerian-type methods. The latter require extensive calculations to be carried out in very small time steps and at numerous locations. Finally, because of its Lagrangian nature, the wave characteristic method is less sensitive to the structure of the network and to the length of the simulation than Eulerian-type methods, and allows large systems to be accurately analyzed in an expeditious manner.
In order for a user of InfoSurge to be confident of the results, their pipe system must conform to the assumptions made in the program and they must properly describe their piping network and the conditions that are causing the transient to occur. Errors in any of these areas may lead to incorrect results. Decisions made on the basis of incorrect results may lead to undesirable consequences.
InfoSurge is not meant to supplant good engineering judgment. It is meant to be a tool that will assist water utilities in analyzing their systems for transient conditions. The program will not make design or operating decisions, but will provide information, which, if properly obtained and properly interpreted, will aid utilities in making these decisions. The user is referred to the InfoSurge support team for answers to questions, which arise and for guidance in applying the program.
Our high-level, state-of-the-art research and development effort in transient flow analysis is continuing at a rapid pace and we intend to update and refine InfoSurge to reflect this progress. We are pleased to be at the forefront of this sophisticated computer modeling technology and to continue to advance it to an unprecedented level of reliability, versatility, ease of use, and performance.