Go Back   986 Forum - The Community for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Post Reply
 
LinkBack Thread Tools Display Modes
Old 04-01-2014, 01:48 PM   #1
I am my own mechanic....
 
Timco's Avatar
 
Join Date: Feb 2013
Location: Salt Lake City, UT
Posts: 3,433
I guess this would be a physics question...

So I fill the large dog bowl on the deck with a hose. With the hose fully on, if I touch the bottom of the bowl with the hose end, it is attracted or sticks to the bottom.

How does that work???

__________________
'04 Boxster S 50 Jahre 550 Spyder Anniversary Special Edition, 851 of 1953, 6-sp, IMS/RMS, GT Metallic silver, cocoa brown leather SOLD to member Broken Linkage.
'08 VW Touareg T-3 wife's car
'13 F150 Super Crew long bed 4x4 w/ Ego Boost
Timco is offline   Reply With Quote
Old 04-01-2014, 02:06 PM   #2
Custom User Title Here
 
particlewave's Avatar
 
Join Date: Mar 2012
Location: Ft. Leonard Wood
Posts: 6,163
Garage
I believe you are referring to an aspiration effect, similar to quick deploy air filled devices (aircraft emergency slides, life raft, etc). The water rushing out is pulling the surrounding water with it, creating an area of low pressure. The weight (pressure) of the water outside this zone is greater than within it.

If the bottom of the bowl is curved, could be a reverse lift effect, similar to an airfoil or hydrofoil.
Sound right?
__________________
https://youtube.com/@UnwindTimeVintageWatchMuseum

Last edited by particlewave; 04-01-2014 at 02:11 PM.
particlewave is offline   Reply With Quote
Old 04-01-2014, 02:33 PM   #3
Registered User
 
jb92563's Avatar
 
Join Date: Apr 2012
Location: Riverside, CA
Posts: 1,665
Yes, Bernoulli effect.

Similar effect to blowing across the top of a sheet of paper, high speed flow creates low pressure which pulls the paper up towards the higher speed air.

or ping pong ball suspended in midair in blower air stream. Higher speed air keeps ball in center of air stream as thats where the lower pressure is.

or aircraft wing (Spoiler), lower curved surface makes the airflow accelerate and hence creates lift in the down direction on the lower side towards the faster moving air stream.

or car air dam that forces the air through a smaller gap between air dam and road causing airflow to speed up and that is what creates the suction that helps keep the car in contact with the road.
__________________
"It broke because it wants to be Upgraded "
2012 Porsche Performance Driving School - SanDiego region
2001 Boxster S, Top Speed muffler, (Fred's) Mini Morimotto Projectors, Tarret UDP,
Short Shifter, Touch Screen Dual Din Radio, 03 4 Bow glass Top (DD & Auto-X since May 17,2012)
jb92563 is offline   Reply With Quote
Old 04-01-2014, 02:33 PM   #4
Beginner
 
Jamesp's Avatar
 
Join Date: Mar 2013
Location: Houston
Posts: 1,659
Garage
When a given volume of fluid moves through a restriction, it speeds up and the pressure drops (Bournelli effect). The "attaction" is really the higher outside pressure pushing against the lower presure in the faster moving fluid squirting through the gap between the hose and the bowl. This principle is what make carburetors work. It can also be demonstrated by taking a 3x5 card, a pin, and a spool of thread. Poke the pin through the middle of the card, inset the pin into the hole at one end of the spool, then blow through the other end of the spool. The card sticks to the spool because the air speeds up between the face of the spool and the card. The more air that goes through the spool, the harder the card sticks.
__________________
2003 S manual
Jamesp is offline   Reply With Quote
Old 04-01-2014, 07:21 PM   #5
Autobahn Glanz
 
WhipE350's Avatar
 
Join Date: Dec 2010
Location: Charlotte, NC
Posts: 1,282
Garage
This forum is still the best!
WhipE350 is offline   Reply With Quote
Old 04-01-2014, 08:56 PM   #6
Custom User Title Here
 
particlewave's Avatar
 
Join Date: Mar 2012
Location: Ft. Leonard Wood
Posts: 6,163
Garage
Whip! How's it going buddy?
__________________
https://youtube.com/@UnwindTimeVintageWatchMuseum
particlewave is offline   Reply With Quote
Old 04-02-2014, 05:22 AM   #7
Autobahn Glanz
 
WhipE350's Avatar
 
Join Date: Dec 2010
Location: Charlotte, NC
Posts: 1,282
Garage
Quote:
Originally Posted by particlewave View Post
Whip! How's it going buddy?
Hey man! Well I've been hanging out on the other forum where they all have new 981s. Having sold both my 986 and 987 I'm not doing much machanical stuff now a days. The highlight of my 981 is a pulled an air filter for the fun of it and changed the oil. I come over to 986forum when I need a little brain stimulation.

WhipE350 is offline   Reply With Quote
Post Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 06:05 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page