Version 4.2 - Visual Hydraulics Analysis Software
- Model the flow distribution between multiple flow paths
- Add parallel and bypass streams
- Take the guesswork out of what flow is going where!
- Combining/dividing Tees
- Channel transitions
- Rectangular notched weirs
- Set parameter defaults
- Modify coefficients and hydraulic factors
- Set up Visual Hydraulics to meet your needs
- Critical elevations feature
- Flow management feature
- Multiple hydraulic scenarios as part of a single file
The biggest advancement in Visual Hydraulics 4.2 is the development of the flow split distribution analysis tool. It also represents one of the most challenging tasks in treatment plant analysis. Although proper design procedures stress the need for measures to be implemented to insure appropriate flow split between multiple units, this often does not occur and may not even be possible.
The hydraulic process of analyzing how flow is distributed among various paths can be extraordinarily complex, depending on the nature of the flow paths and the number of flow paths that must be calibrated throughout the hydraulic profile. Visual Hydraulics uses the concept of 'equalized head', which is the principle that the flow will be distributed among various paths until the water elevation upstream of all of those paths has achieved an equal water surface elevation. Therefore if more head is required to pass flow through one path, less flow will be conveyed to that path and more flow will be conveyed to the path that requires less head. A balanced system has equal head losses across all flow paths and the sum of the flows through each flow path will add up to the total flow.
Consider the following very basic flow path split:
In the scenario above, the system is considered to be balanced. The water surface elevations downstream of the flow split are equal, therefore the amount of flow being conveyed to each path is correct. This is a very simple case, with the two pipes comprising the separate flow paths being exactly equal. If a simple change is made to the profile so that the pipes are not equal, the water surface elevations for each pipe will vary:
In this case, the water surface elevations upstream of the two pipes are not equal, and this system is therefore unbalanced in terms of flows. More flow should be conveyed through flow distribution pipe 2 than flow distribution pipe 1, and vice versa. The challenge lies in determining how much flow should be distributed through each path, and that's when the flow distribution tool provided within Visual Hydraulics 4.2 can be used. The user would simply instruct the software to perform a flow distribution analysis on the hydraulic profile, and when this is done, the software will determine the appropriate flow for you:
The example presented previously is the most simplistic case of a flow distribution analysis. Most flow distribution analyses are much more complex and involve items such as weirs, flow paths off-line, and many flow splits and flow paths to consider. Visual Hydraulics 4.2 has been designed to handle a variety of flow split scenarios. An example of a unique flow split situation is the scenario where no flow may be conveyed to a flow path. This type of situation could occur if an overflow path exists in the hydraulic profile. Consider the following sample hydraulic profile:
In the example above, the normal mode of operation would be for all of the flow to follow the 'normal path', or lower path. The flow path with the 'overflow weir' element would only come on-line if high flows were encountered. In this case, the user guesses that portion of the flow will go through the bypass path, with the remaining flow being conveyed through the normal path. To check that assumption, a flow distribution analysis can then be performed:
As can be seen from the adjusted hydraulic profile, it turns out that the bypass weir ('overflow weir') actually does not receive any flow because the other flow path can safely pass all of the flow before the weir elevation is reached. If this situation is encountered by the software, the path will display a 'No Flow' label above the hydraulic element so the user is made aware that flow is not conveyed to that section of the profile.
The flow split analysis tool is the most advanced and complex tool we have ever had as part of our Visual Hydraulics software. Take the guesswork out of hydraulic profiles with multiple flow paths...let Visual Hydraulics 4.2 do the work for you!
The combining/dividing tee presents a very unique challenge theory wise. No set equations have been developed for the hydraulic analysis of these tees, only graphs based on extensive testing done by D.S. Miller (published in Internal Flow Systems, copyright D.S. Miller). Innovative Hydraulics has taken the time to analyze these graphs and develop K value tables based on the data presented in the graphs, and those K value tables have been included as part of Version 4.2. Based on the information provided by the user (diameters of the tee, approximate flow split, and angle of the tee), the software determines a K value, which in turn is used to determine the appropriate head loss.
Open Channel Contraction/Expansion:
It is not uncommon to encounter a channel that changes width, and this change in width is typically done as a transition rather than abruptly. Transitions may be either channel contractions or expansions. Based on the information provided by the user (type of transition, respective widths of the channel, channel invert, and flow), the software will determine a K value for the transition's characteristics. This K value is then multiplied by the velocity in the channel to determine the relative head loss of the transition.
Rectangular Notched Weir:
The rectangular notched weir is very similar in operation to the v-notch weir, with the rectangular notches provided more flow capacity than the v-notch. Typical installations of the rectangular notch occur as clarifier or other process tank effluent weirs. Single larger rectangular notch weirs may be used in some scenarios. For analysis by Visual Hydraulics 4.2, the user provides the invert of the weir notches, size of the notches, number of notches, and flow over the weir.
As can be seen from the element options tab above, the element type is provided on the left side of the form, and the corresponding coefficients that are stored in the software are presented in the table to the right. For pipe fittings, a K value can be changed at any time, and a fitting can be added or removed from the database if desired. If the user were to select the rectangular weir element, the table would be updated to include the respective 'C' values for weirs stored within the software:
Visual Hydraulics 4.2 saves the original values provided for the various coefficients, so if the user desires to go back to the default value provided with the software, it can be done at any time by simply restoring the default value.
Element Flexibility - Different Theories
In addition to varying coefficients for equations, the general theory for a hydraulic element may have more than one accepted methodology. Consider the bar rack/screen element. More than one theory is widely publicized for analysis of bar racks/screens. Because of this, Visual Hydraulics 4.2 offers the user with the option of selecting a particular theory for analysis:
The user can select a theory for analysis or run both theories and compare the results.
Many additional features have been added to Version 4.2, more than can be covered here. But we felt it would be worthwhile to give you a few more examples of how powerful the software can be. Visual Hydraulics is constantly being improved based on the input we receive from users around the world. As those suggestions come in, we give them thorough consideration and determine if a suggestion will indeed make the software more powerful. Many suggestions have, and here are just a few more of those additional options that have been added:
Critical Elevations Feature:
Is it not uncommon for there to be elevations that are crucial to the proper analysis of a hydraulic profile, elevations that must be maintained or minimized to insure that the overall hydraulic behavior of the system is not compromised. Examples are submerged weirs, overflowing channels, and manufacturer required elevation set points for equipment. Visual Hydraulics has a built-in feature that allows the user to set a critical elevation for any section of the hydraulic profile, and that feature will flag the user if that critical elevation is ever reached during an analysis. The user simply provides the software with the critical elevation, and if that elevation is encountered during analysis, the user is flagged:
In this case, the user had provided a critical elevation of 703.2, which was reached during the hydraulic analysis. The critical elevations feature provides an additional level of support information to insure that the design is not compromised.
Flow Management Feature:
One of the suggestions that we received was to place a flow management feature within the software that would allow the user to change the relative flow values for any or all of the elements from one single location, rather than editing the elements individually. Visual Hydraulics 4.2 now has this feature, which is shown above. The user can enter either a flow value or a flow percentage for any element within the hydraulic profile from this location.
Multiple Hydraulic Scenarios:
One of the new features of Version 4.2 is the ability for the user to model up to 5 different hydraulic profile scenarios as part of one file. Previous versions did not have this capability. This allows the user to try different options and save those changes within one file, greatly increasing the flexibility of the software: