Venturi Design

For some things there are NO shortcuts. Go and study fluid mechanics. Does the name Bernoulli mean anything to you??

thank u for ur reply. i do know what si bernoulis and i do knoe abt the fluid mechanics involved.i know abt the theory but the desinging part is not exactly my area of expertise and i have been given the job to design the venturi.the design that was proposed by one of my heads, i found it to be inappropriate because the beta i.e. the d/D ratio was only 0.166 bt i have read that it shld be in the range of .3-.75.

so if i want to point that out to him i shld be prepared with a better design and dnt want to make a fool out of my self. i hope u understand.thank u for ur intrest once again.

First, search for old threads on here. We've talked about this before. Second, there are no complete theoretical ways to deal with this. You van model it in any CFD program, but sooner or later you'll have to build some prototypes and test them. You can buy several commercial units fairly inexpensively and get some ideas there.

ok i will see what can be done. thanks a million for ur help.

if u get tym check out this link.

http://nepis.epa.gov/Exe/ZyNET.exe/500013ZU.txt?ZyActionD=ZyDocument&Client=EPA&Index=1981%20Thru%201985&Docs=&Query=%2845%20degrees%29%20OR%20FNAME%3D%22500013ZU.txt%22%20AND%20FNAME%3D%22500013ZU.txt%22&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&UseQField=&IntQFieldOp=1&ExtQFieldOp=1&XmlQuery=&File=D%3A%5CZYFILES%5CINDEX%20DATA%5C81THRU85%5CTXT%5C00000014%5C500013ZU.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=10&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=p%7Cf&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=11

the terms and conditions for the inlet throat and the diverting sections are a little tricky. if u do under stand let me know. i will be going for the classic model.

I looked at the spec. I cannot spare three or four hours to look at every detail, so I have to give you a "seat-of-the-pants" estimate.

I've built several gas sampling venturis that performed somewhat like what this asks for, so I think I understand the basic criteria. And, I can do a little CFD. However, I wouldn't even know where to start on this spec. When they talk about "unlimited Reynolds number", for instance, I can just imagine a budget melting away like an ice cream cone in Bakersfield in July.

Good luck to you. I hope you figure it out.

The flow equates to about 21 gpm, for which a 3-inch inlet seems rather large. ??

The mixture of inch and mm units also seems a bit odd.