Featured Research

from universities, journals, and other organizations

Ketchup turns somersaults

Date:
March 7, 2013
Source:
Technische Universitaet Muenchen
Summary:
Blood, paint or ketchup are complex liquids composed of several different components. For the construction of pumps, or the improvement of technical processes scientists and engineers need description models. They make the special properties of such liquids predictable. Researchers have now developed such a model.

Why ketchup turns somersaults - the extraordinary behavior of complex fluids.
Credit: Markus Harasim / TUM

Blood, paint or ketchup are complex liquids composed of several different components. For the construction of pumps, or the improvement of technical processes scientists and engineers need description models. They make the special properties of such liquids predictable. Researchers at the Technische Universitaet Muenchen (TUM) and the Federal Institute of Technology Zurich (ETHZ) have developed such a model. In the current issue of the journal Physical Review Letters they present it.

The unusual behavior of complex fluids is part of our daily life: cake dough climbs up the stirring bar, ketchup becomes liquid when you shake it. Also technology uses such phenomena: if we add a small amount of long-chained polymer molecules, a pipeline can transport more oil. The polymers reduce the flow resistance. But up to now the origin of these effects was unclear. The engineers had to rely on estimates and lengthy trials.

A team of physicists led by Professor Andreas Bausch, Chair of Cellular Biophysics at TUM now developed a numerical model of such liquids. Experimental heart of the work are a fine flow channel and a micro-camera. Like the camera looking down at the pit lane of Formula 1 races, the scientists monitored the movements of individual polymer molecules in the flow.

From their observations they conducted a theoretical model for the motion of rigid molecules different from the current. In addition, they were able also to provide for colleagues suspected of movement patterns experimental confirmation.

Challenging for theory and experiment

"Due to the incredibly large number of degrees of freedom the study and description of the motion of polymers is a big challenge," says Markus Harasim, one of the two main authors. Even a simple system of water and polymer shows the effects of complex fluids. In order to make the long molecules visible, the physicists marked the polymers with a fluorescent dye. This allowed them to study the movements under various conditions.

To their surprise the mathematical modeling showed, that even the simple model of a stiff rod was suitable as a starting point. Then the researchers refined the model by taking into account the thermal motion, the flexibility of the molecule and the higher flow resistance of a curved polymer. "Since we now know the microscopic mechanisms, we can extend the model to more complex geometries and flows. And thanks to our experimental set-up we should be able to verify our theories," says co-author Bernhard Wunderlich, who is a well known rapper in the hip-hop band "Blumentopf" in his off time.

The work was funded by the German Research Foundation Center's research and the Cluster of Excellence Nanosystems Initiative Munich (NIM).


Story Source:

The above story is based on materials provided by Technische Universitaet Muenchen. Note: Materials may be edited for content and length.


Journal Reference:

  1. Markus Harasim, Bernhard Wunderlich, Orit Peleg, Martin Krφger, Andreas R. Bausch. Direct Observation of the Dynamics of Semiflexible Polymers in Shear Flow. Physical Review Letters, 2013; 110 (10) DOI: 10.1103/PhysRevLett.110.108302

Cite This Page:

Technische Universitaet Muenchen. "Ketchup turns somersaults." ScienceDaily. ScienceDaily, 7 March 2013. <www.sciencedaily.com/releases/2013/03/130307124657.htm>.
Technische Universitaet Muenchen. (2013, March 7). Ketchup turns somersaults. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2013/03/130307124657.htm
Technische Universitaet Muenchen. "Ketchup turns somersaults." ScienceDaily. www.sciencedaily.com/releases/2013/03/130307124657.htm (accessed July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) — 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com
Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) — Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Car Market on the Rebound?

Europe's Car Market on the Rebound?

Reuters - Business Video Online (July 23, 2014) — Daimler kicks off a round of second-quarter earnings results from Europe's top carmakers with a healthy set of numbers - prompting hopes that stronger sales in Europe will counter weakness in emerging markets. Hayley Platt reports. Video provided by Reuters
Powered by NewsLook.com
9/11 Commission Members Warn of Terror "fatigue" Among American Public

9/11 Commission Members Warn of Terror "fatigue" Among American Public

Reuters - US Online Video (July 22, 2014) — Ten years after releasing its initial report, members of the 9/11 Commission warn of the "waning sense of urgency" in combating terrorists attacks. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins