Transducer bubble diverter

 I have had three transducers on the boat in the normal position without much success. I have put a TM260 way out to the side to get it to work.

I had some success with a totalscan sikaflexed straight to the bottom of the hull.                                                                                                                                              I have always believed it is the hull creating bubbles so I decided to try and make something to divert the bubbles away from the transducer so I just sikaflexed a piece of thin ally plate in front of the transducer to try and send bubbles away from the transducer it actually worked. Doing 24 MPH in 35m it was working great.

This could be something for Gruntre to investigate for his problems.

Keep in mind I am not an expert on water flow [just a dumb sparky] so I may have just got lucky.

 

 

 

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Grumbler's picture

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Interesting. Thanks for

Mon, 2018-09-24 15:27

Interesting. Thanks for sharing. I was thinking about something like this for my totalscan. Looks like it worth to try.

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Interesting

Mon, 2018-09-24 16:18

 is the front of the totalscan flat ( vertical ) ? . If so you might want to get some wood and make a bullet head for it to streamline it . If you wanted to get super fancy make a resin one ... :) . If you’re anal about drag you can make one for the rear too. 

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crano's picture

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Silver fox

Mon, 2018-09-24 18:55

 Yes it is in front. I will make something like a proper fairing block. I also am considering ditching my bit of ally and just trying it with a 10 or 12mm spacer and seeing this gets it clear of the bubbles.

Grumbler's picture

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Mine sits on flush mount

Tue, 2018-09-25 11:59

Mine sits on flush mount bracket. It gives about 16mm separation from the hull. I am still having problem with signal. Picture is clear up to 11 knots, then degrades slightly to about 13 knots. After that it begins to break. Bottom looks like dashed line with spaces filled with noise from top to bottom. This is an improvement since I moved transducer to the bottom from its original location on the transom. There it was loosing bottom completely at 15-18 knots.

gruntre69's picture

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 Thanks mate,Yes this is on

Mon, 2018-09-24 18:59

 Thanks mate,

Yes this is on my radar, I'm thinking of doing a test with something like this. I'd very much like to see before and after sounder shots with similar setting, conditions and speed...

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crano's picture

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Gruntre69

Mon, 2018-09-24 19:34

 Essentially just a very stop start picture before, now all the the missing bits are there.

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Nice one

Mon, 2018-09-24 21:21

You’re the smartest sparky I’ve come across. Look forward to seeing the final result . 

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scubafish's picture

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deflector

Tue, 2018-09-25 08:27

I would say you are probably creating more bubbles with the shield there than not.

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Agreed

Tue, 2018-09-25 10:33

I agree. Turbulence and cavitation behind that plate at high speeds I would think. Would be better off designing some sort or "smooth" bulb on the hull to disperse and bubbles away from the transducer

gruntre69's picture

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 Conventional wisdom is with

Tue, 2018-09-25 10:51

 Conventional wisdom is with the comments shown but the proof is in the pudding. This is why I wanted to see the screen shots... It looks like a massive turbulence creator but I really don't know how much turbulance affects sounders. I'm certain that air bubbles are the worst enemy..

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Lowrance flush mount fitting

Tue, 2018-09-25 16:31

Lowrance do make a flush mount fitting for under the hull I think. CH Smith have them, just google 3D transducer flush mount bracket.  Has anyone used one of these as mine is crap at any speed.

 

 

crano's picture

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scubafish

Tue, 2018-09-25 20:27

 I agree it goes against what should happen in theory but it worked in this case. I did not really think it would work but for ten minutes work was worth a try.

The TM 260 is still a lot better option when travelling but I like the idea of a 15 degree beam  that the totalscan has compared to six degrees on the TM 260 for finding new ground.

I will try to make something a bit less agricultural one day

Alan James's picture

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...

Wed, 2018-09-26 11:04

I always remember this portion of the problem solving flowsheet.

Does the damn thing work  -->  Yes  --> Don't fuck with it  -->  No problem 

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scubafish's picture

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trany

Wed, 2018-09-26 10:19

Hey Crano,what was causing the bubbles in the first place and how long is the boat ?

I have a simm prob with mine as it is only 17ft Bubbles are created from the bow as I dont displace enough water to get clean water under the boat,side scan trany still off the back but will only operate at low speed when the boat displaces the most water with bow down on trim.
Just a suggestion,try to make the front edge of the trany a bit more like a strake than a deflector (mould and taper off)

Fluid flow is generally broken down into two different types of flows, laminar flow and turbulent flow. Laminar flow is fluid motion in which all the particles in the fluid are moving in a straight line.

http://www.reactor-physics.com/engineering/fluid-dynamics/laminar-flow-vs-turbulent-flow/

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crano's picture

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scubafish

Wed, 2018-09-26 17:21

 The boat is a 6m signature. I am obviously only assuming it is creating bubbles as nothing works around this part of the hull. With the TM260 I made a bracket that was adjustable up and down and angle of transducer with out any luck.

Had a quick look at the fluids link. looks like an interesting read and I hope I can learn something from it.

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Crano,

Wed, 2018-09-26 21:13

all good mate trial and error is the best way to go and the process is a lot of fun as well.I put in a P79 thru hull works ok dont notice any loss in sensitivity but ok for my small boat,holds bottom at a reasonable speed rear transom just didn't work.trial and error good luck and have fun.

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