Sketchy Skeptic

Hi,

I would like to produce a water flow of 15 gal/min (0.0009463m^3/s) in a pipe with a diameter of (1.8897 in/48mm). This would be with the source tank level with the pump and the outlet of the system level with the pump, and into open air. I believe I need a pressure of 101.461kPa to produce this flow (ignoring friction and resistances). Assuming, the pump is rated for the flow rate of 15gal/min, would I need a minimum pump head of 33.95 ft-head (101.461 kPa)?

Thanks for your help!

Hi,

If I know the volumetric flow rate of water through a pipe, and the density of water, and I know the pipe opens to air on the output side, can I simply calculate the pressure that would be required at the output to push that water through the pipe (ignoring fiction and pipe bends)?

If the pipe opens to the air at the end, is the pressure along the pipe a gradient that begins high at the pump, and is equal to atmospheric pressure at the end of the pipe?

As a follow up question, am I correct in assuming that adding a choke would not affect the overall volumetric flow rate, and so I can assume the pressure before and after the choke would be the same as if there was no choke at all?

Thank you very much for your help!

Hi, I need help figuring out how to calculate the approximate pressure in a portion of pipe leading into a Venturi tube. The pipe is not real yet, so I can’t just use a gauge to check (the results of the calculation and future calculations will determine the design of the pipe). For example values, the pipe is a fed by a pump that feeds a volumetric flow of 0.0063m^3/s (100gal/min), the pipe radius is 6cm, the pipe reaches a 45 degree taper where is reduces down to a restriction (say, 1cm) for some small distance and then opens up back to 6cm at some taper (say, 45 degrees). It ultimately opens to empty in a holding tank, open to the air.

The one value I will know and cannot change is the volumetric flow rate.

Ultimately, I will change the restriction size so that I can achieve a specific desired pressure at the choke. I know I can do this with Bernoulli’s equation, but I need to first estimate the pressure in the first part of the pipe.

I don’t know the material of the tube yet (probably acrylic), so I can’t determine the friction. I am mostly just looking for estimates right now, but advice on increasing accuracy when I have more information would be greatly appreciated

Hi, I need help figuring out how to calculate the approximate pressure in a portion of pipe leading into a Venturi tube. The pipe is not real yet, so I can’t just use a gauge to check (the results of the calculation and future calculations will determine the design of the pipe). For example values, the pipe is a fed by a pump that feeds a volumetric flow of 0.0063m^3/s (100gal/min), the pipe radius is 6cm, the pipe reaches a 45 degree taper where is reduces down to a restriction (say, 1cm) for some small distance and then opens up back to 6cm at some taper (say, 45 degrees). It ultimately opens to empty in a holding tank, open to the air.

The one value I will know and cannot change is the volumetric flow rate.

Ultimately, I will change the restriction size so that I can achieve a specific desired pressure at the choke. I know I can do this with Bernoulli’s equation, but I need to first estimate the pressure in the first part of the pipe.

I don’t know the material of the tube yet (probably acrylic), so I can’t determine the friction. I am mostly just looking for estimates right now, but advice on increasing accuracy when I have more information would be greatly appreciated.

Thank you very much for your help!

It was a guys singing and towards the middle/end of the song, this gate is rising and a woman is behind it, kinda moving to the beat. When the gate rises, she comes out singing. I know its not much to go on, but this is driving me crazy. Thanks in advance!

I'm somewhat new to music theory and would like to truly understand it, not just memorize, so I can use it properly. I'm looking for a little more of an explanation that "because that's the way Western music is".

I would like to know why in a major scale we call E->F a half step and B->C a half step. An octave is a doubling of the frequency of a note, and I assume the notes A->G are spaced by some relationship of frequency (I would appreciate this relationship if you know). What I really want to know is, does this relationship of frequency actually change between E->F relative to D->E (i.e. is the expected jump in frequency between notes halved or something?) and if so, why does it sound good (do they sound like a half an interval the trained ear?), and why would they bother giving them major letter names- just laziness when making major scales?

I know that's a lot of questions, but if you can answer them, you will have probably changed my entire outlook on music. Thanks in advance!

Cheers!

I'm somewhat new to music theory and would like to truly understand it, not just memorize, so I can use it properly. I'm looking for a little more of an explanation that "because that's the way Western music is".

I would like to know why in a major scale we call E->F a half step and B->C a half step. An octave is a doubling of the frequency of a note, and I assume the notes A->G are spaced by some relationship of frequency (I would appreciate this relationship if you know). What I really want to know is, does this relationship of frequency actually change between E->F relative to D->E (i.e. is the expected jump in frequency between notes halved or something?) and if so, why does it sound good (do they sound like a half an interval the trained ear?), and why would they bother giving them major letter names- just laziness when making major scales?

I know that's a lot of questions, but if you can answer them, you will have probably changed my entire outlook on music. Thanks in advance!

Cheers!

I'm somewhat new to music theory and would like to truly understand it, not just memorize, so I can use it properly. I'm looking for a little more of an explanation that "because that's the way Western music is".

I would like to know why in a major scale we call E->F a half step and B->C a half step. An octave is a doubling of the frequency of a note, and I assume the notes A->G are spaced by some relationship of frequency (I would appreciate this relationship if you know). What I really want to know is, does this relationship of frequency actually change between E->F relative to D->E (i.e. is the expected jump in frequency between notes halved or something?) and if so, why does it sound good (do they sound like a half an interval the trained ear?), and why would they bother giving them major letter names- just laziness when making major scales?

I know that's a lot of questions, but if you can answer them, you will have probably changed my entire outlook on music. Thanks in advance!

Cheers!

I'm having an argument with my girl about the KFC macaroni salad (not the mac and cheese) originally being orange here in Canada. They changed it to its white form at some point in the last 10 years, but I need some testimony that others remember this. It would be helpful if you could remember when it changed over too.

Thanks- Cheers!

I just got into a Masters program in something l enjoy. I dont feel like I'm finished school and think I should continue beyond my BSc. My girlfriend wants to be a vet and has a career based job in her hometown. Weve been long-distance for 2yrs and if I got to school where I want and she does her vet thing, it will be years before we get to live together. She wants me to move to her town and I dont think I could ask her to give up a job that could help her reach her dream to come to live with me.

Shes going crazy being apart (2.5 hrs) and I don't think she can handle it how it is. I try to see her when I can but thats every 4-6 weeks, and shes too busy to come to see me. We talk each night. She needs human touch, but I feel like 2 yrs isnt too long to wait to live together if we love eachother. She takes it as I dont love her enough to not go to school and live with her. I dont think I could get in again if I give up now. We need some middle ground- I cant see any. Any creative ideas?