Is there a chart/graph of the gph output of the WAV as a function of the power %?
Is there a chart/graph of the gph output of the WAV as a function of the power %?
As far as I am aware, it's essentially linear. However 1% will not be 1% of 4000gph but some higher number. I have not seen actual measurements, but based on claims on the forums, I would guess 1% is roughly 500 gph. If that is indeed the case, a good approximation of flowrate would be
Flowrate = percentage * 3500 + 500
Or if you want to find the ideal percentage
Percentage = (flowrate - 500) / 3500
You might be an engineer if...You have no life and can prove it mathematically.
I don't mean to appear disrespectful by questioning what you said, but your use of the statements "as far as I am aware" and "based on claims on the forums" leads me to wonder if you are 100% positive. Here is what I see in Fusion:
WAV percent.jpg
One could infer from your statement "However 1% will not be 1% of 4000gph but some higher number." that the % sign we see in Fusion is a percentage of max gph. Is that the case for certain, or could it be a percentage of max power?
I am not a fluid mechanics guy, so please feel free to correct me if I'm wrong, but to me, fan affinity laws don't appear to support your claim that the flow to power line is linear. Flow to impeller speed is linear because they are directly proportional, but by substitution, flow is proportional to the cube root of power. That line curves.
RussM said last year that the WAV draws 26W at max power, and we know that the WAV puts out 4000 gph at max power, so starting there, here is my math:
Fan Affinity Law math.jpg
I would expect the line to look something like this:
Flow to Power graph.jpg
If I'm correct, you get half of your max flow (2000 gph) from the first 3 watts of power. It takes another 23 watts to get the other 2000 gph. I would be very interested in having a Neptune Systems guru weigh in here. Is the percentage given as a function of max flow or max power? If it's a function of max power, is there an official chart/graph of the flow to power correlation? And lastly, is my math right?
You math is correct for a frictionless pump and if the percentage was the power delivered to the pump. The WAVs percentage is not exactly power though (if it was it wouldn't turn on at 1%) and overcoming static friction causes a quick jump from zero to some value because kinetic friction is much lower. I recall but am not 100% certain that Neptune said the internal conversion from percentage to pump power was modified to be non-linear such that percentage would more closely follow flow rather than power and that the minimum power is enough to turn on at 1% (I do know for certain that the COR is non-linear for power from a thread about watts usage a couple weeks ago and I assume they use a similar conversion). Exactly how close this is to linear is not published and exactly what the minimum flowrate is also not published.
If you are targeting a specific flowrate, the easiest way would be to determine the RPM required to achieve the desired flowrate and then just use trial and error to reach that RPM value.
I don't own a WAV to test, but you could build a curve pretty easily just by writing down the RPM values at each percentage (on constant) and assume that the flow at maximum RPM is 4000 gph and that flow is perfectly linear with RPM (it won't be because of turbulence but it's close enough to get a reasonable approximation)
You might be an engineer if...You have no life and can prove it mathematically.
I was shooting for 6000 gph (30 tank turnovers / hr). I went ahead and plotted it. I got this:
WAV RPM per Pwr Percentage Graph.jpg
The max RPMs I could get was 4137 give or take 20. The graph looks to be linear as a percentage of the difference between the minimum 1863 and maximum 4137 RPMs. Assuming rpms are proportional to flow, the 4137 approximates close enough the 4000 max gph advertised for the WAV, so I just called them equivalent. The % is a function of the flow as shown on the graph. If my math is correct, each 1% "power" adds approximately 23 gph per WAV, starting at 1863 gph. I need 6000 gph, so I need to set each WAV on 50% "power". Now all I need is to understand better how the malibu and maverick profiles work. I get the generality that malibu is more calm than maverick, but I can't find information on the min and max power they cycle through. If I set the WAV on Malibu or Maverick at 50%, what will my minimum and maximum power %s be as the WAV goes through the profiles?
I looked a bit myself and the responses I found from Russ appear to infer that the set percentage is the maximum but it's hard to say for sure. My gut would expect the set percentage to be average though.
You might be an engineer if...You have no life and can prove it mathematically.
A large part of my frustration comes from the lack of up to date, robust documentation. I shouldn't have to hunt through forums looking for what I believe most users would consider basic information, only to find it and then not really be sure the posted information is correct. There is a massive amount of "I'm not sure, but I think..." in user forums. Literally, the only "official" profile documentation I could find was in the WAV Quickstart Guide. It's a picture of the profile graphs, and a very brief description of what they do. There isn't any instruction about how to effect the actual programming. For example, tonight I found a post by jonmos75 showing how to set the slave's inverse setting.
WAV Inverse Slave Setting.jpg
That should have been in the documentation.
BTW, I know you answer at least 2 or 3 posts a day . That takes a lot of time you could be spending doing other, more fun, things. I appreciate all you do to help this forum, but I feel bad for taking your uncompensated time. I also know that you're not omniscient. Is there away for you to shout out to Russ or a Neptune support rep to get them to weigh in here? I need more information about the Malibu and Maverick cycles.
I want to set my two WAVs on the profile as a master and inverse slave so the alternating heavy flow will move the point of confluence back and forth across my tank. If I set the master to 50%, and the slave to 100% as shown in jonmos75's screen shot, and the master goes to zero, will the slave go to 100%, or to 100% of 50%? I suppose I could experiment with the settings and plot the actual rpms as they cycle, like I did above, but I would rather be doing other, more fun things, too. Someone, somewhere, knows the answer.
Are the Malibu or Maverick flow patterns independently random for each WAV, or do they follow a preset pattern that restarts at a set time (at midnight, for example)? If they're random and independent, then couldn't I blow off the inverse setting altogether, set them both on the regular profile, and wouldn't the confluence point move randomly anyway?
P.S. Is there a way to size a picture after inserting it into a post? This one turned out to be reeeealy big.
Last edited by rlbannon; 03-01-2018 at 22:51. Reason: Post Script
Hi Zombie, No one replied to my last few questions. Do you mind taking a stab at them? I would also like to hear from RussM. Is there a way to tag him in this?
- What are the lower intensity limits for the Malibu and Maverick profiles if I set them to 50%? Will they ever go to zero?
- I want to set my two WAVs on the profile as a master and inverse slave so the alternating heavy flow will move the point of confluence back and forth across my tank. If I set the master to 50%, and the slave to 100% as shown in jonmos75's screen shot, and the master goes to zero, will the slave go to 100%, or to 100% of 50%?
- Are the Malibu or Maverick flow patterns independently random for each WAV, or do they follow a preset pattern that restarts at a set time (at midnight, for example)? If they're random and independent, then couldn't I blow off the inverse setting altogether, set them both on the regular profile, and wouldn't the confluence point move randomly anyway?
I don't remember, so I would just be searching through old threads to find that out. JonMos or Russ probably know off the top of their heads.
You might be an engineer if...You have no life and can prove it mathematically.
SOLVED: I ended up just starting a ticket with Neptune Support. I received a phone call with some answers, and then a ticket answer with the rest. My questions are in black, Neptune's answers are in blue (paraphrased to combine information from both sources):
Background: I have a 240 gallon, 2016 Apex controlled system, with two WAV units mounted near the back on opposite ends of the tank, with their respective flows pointed at the center of the front tank glass. I want to program them with different intenstity-changing flow profiles, such that, as the intensities vary from side to side, the alternating high/low flow will move the point of confluence back and forth across my tank. I am considering the Malibu and Maverick profiles, with one WAV as a master, and the other as an inverse-slave.
1. The WAV Quickstart Guide says the profile flow intensity patterns are random. Does the controller compute a truly random intensity cycle, or is it really a predefined pattern with so many variations that it only appears to be random? It is a predefined pattern which is varies so much over time that it is effectively random. That pattern repeats about every hour and a half.
2. If truly random, are the profiles INDEPENDENTLY random for each WAV? That is to say, does the controller compute a random flow intensity and then send the same intensity signal to every WAV on the system at the same time, or does it compute a different random intensity for each WAV at each moment? If every WAV gets an independently random intensity, then it seems that I wouldn't need to use the inverse function at all. I could just set them both to the same profile, and the confluence would move randomly across the front glass, since each WAV would get a different, random intensity. Use of 2 WAVs running Mavericks will be less effective at creating that moving point of confluence back and forth; use Mavericks and Inverse. (this implies that the patterns are sent to each WAV at the same time.)
3. If the intensities are not independently random, that is, if the two WAVs get the same intensity signal at the same time, then I will need the inverse function. If that's the case, what are the intensity ranges for the master unit under the Malibu and Maverick profiles if I set them to 50%? Mavericks varies between 100% of the configured max intensity and 50% of that value. So, if a WAV is running Mavericks/80% for example, the variations will be between 80% of max and 40% of full WAV power. This is maintained proportionally if the configured intensity is reduced. I'm especially interested in the lower limits and knowing whether they will ever go to zero as they fluctuate. Mavericks and Malibu never go to 0.
4. The Quickstart Guide's explanation of the mirror/inverse functions seems to say that if I set the master to 50%, and the slave to 100% inverse, and the master goes to a certain intensity, then the inverse-slave will go to 50% minus the master's intensity. (example: if the master goes to 15%, the the inverse slave will go to 35%). Extrapolating that, if the master does go to zero, then the inverse slave will go to 50% (100% of the master's 50%). Am I understanding this correctly? If the master is set to 50% of Mavericks and the slave to 100% inverse, then, if the master goes to 50%, the slave will go to 25%. If the master goes to 45% (5% less than max) then the slave will go to 30% (5% more than min). Malibu is similar, but the pseudo-random speed changes are slower and of less magnitude. Malibu varies between 100% of the configured intensity and about 65% of that configured intensity. If you have an intensity you want Maverick to average, divide the desired average intensity by 0.75 to get the required intensity setting. For Malibu, divide by 0.825. For example, I want to use Malibu and I want my intensity to average 50%. Dividing 50 by 0.825 gives me a required intensity setting of 60% for the master WAV.
Last edited by rlbannon; 03-31-2018 at 15:05. Reason: I thought the answers might also have value! :-)
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