External Problem 2: Dimensional analysis and similarity The viscous torque T produced on a disc rotating in a liquid depends upon the characteristic dimension D, the rotational speed N, the density pand the dynamic viscosity u. a) Show that there are two non-dimensional parameters written as: T pND? and b) In order to predict the torque on a disc of 0.5 m of diameter which rotates in oil at 200 rpm, a model is made to a scale of 1/5. The model is rotated in water. Calculate the speed of rotation of the mnodel necessary to simulate the rotation of the real disc. c) When the model is tested at 18.75 rpm, the torque was 0.02 N.m. Predict the torque on the full size disc at 200 rpm. Notes: For the oil: the density is 750 kg m and the dynamic viscosity is 0.2 N.s/m For water: the density is 1000 kg m and the dynanmic viscosity is 0.001 Ns/m. kgm 1N 1
External Problem 2: Dimensional analysis and similarity The viscous torque T produced on a disc rotating in a liquid depends upon the characteristic dimension D, the rotational speed N, the density pand the dynamic viscosity u. a) Show that there are two non-dimensional parameters written as: T pND? and b) In order to predict the torque on a disc of 0.5 m of diameter which rotates in oil at 200 rpm, a model is made to a scale of 1/5. The model is rotated in water. Calculate the speed of rotation of the mnodel necessary to simulate the rotation of the real disc. c) When the model is tested at 18.75 rpm, the torque was 0.02 N.m. Predict the torque on the full size disc at 200 rpm. Notes: For the oil: the density is 750 kg m and the dynamic viscosity is 0.2 N.s/m For water: the density is 1000 kg m and the dynanmic viscosity is 0.001 Ns/m. kgm 1N 1
Chapter2: Loads On Structures
Section: Chapter Questions
Problem 1P
Related questions
Question
![External Problem 2: Dimensional analysis and similarity
The viscous torque T produced on a disc rotating in a liquid depends upon the
characteristic dimension D, the rotational speed N, the density pand the dynamic
viscosity u.
a) Show that there are two non-dimensional parameters written as:
T
PND
and 2
b) In order to predict the torque on a disc of 0.5 m of diameter which rotates in oil at
200 rpm, a model is made to a scale of 1/5. The model is rotated in water.
Calculate the speed of rotation of the model necessary to simulate the rotation of
the real disc.
c) When the model is tested at 18.75 rpm, the torque was 0.02 N.m. Predict the
torque on the full size disc at 200 rpm.
Notes: For the oil: the density is 750 kg/m and the dynamic viscosity is 0.2 N.s/m
For water: the density is 1000 kg/ m and the dynamic viscosity is 0.001NS/m.
kg.m
1N 1](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fc67e7d95-2fc6-4a3e-b642-e8de785fbc8c%2F48f642ec-c4ea-4ed1-9c9c-aa6b2a4950e3%2Fb32vw9qo_processed.jpeg&w=3840&q=75)
Transcribed Image Text:External Problem 2: Dimensional analysis and similarity
The viscous torque T produced on a disc rotating in a liquid depends upon the
characteristic dimension D, the rotational speed N, the density pand the dynamic
viscosity u.
a) Show that there are two non-dimensional parameters written as:
T
PND
and 2
b) In order to predict the torque on a disc of 0.5 m of diameter which rotates in oil at
200 rpm, a model is made to a scale of 1/5. The model is rotated in water.
Calculate the speed of rotation of the model necessary to simulate the rotation of
the real disc.
c) When the model is tested at 18.75 rpm, the torque was 0.02 N.m. Predict the
torque on the full size disc at 200 rpm.
Notes: For the oil: the density is 750 kg/m and the dynamic viscosity is 0.2 N.s/m
For water: the density is 1000 kg/ m and the dynamic viscosity is 0.001NS/m.
kg.m
1N 1
Expert Solution
![](/static/compass_v2/shared-icons/check-mark.png)
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 5 steps with 7 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.Recommended textbooks for you
![Structural Analysis](https://compass-isbn-assets.s3.amazonaws.com/isbn_cover_images/9781337630931/9781337630931_smallCoverImage.jpg)
![Structural Analysis (10th Edition)](https://www.bartleby.com/isbn_cover_images/9780134610672/9780134610672_smallCoverImage.gif)
Structural Analysis (10th Edition)
Civil Engineering
ISBN:
9780134610672
Author:
Russell C. Hibbeler
Publisher:
PEARSON
![Principles of Foundation Engineering (MindTap Cou…](https://www.bartleby.com/isbn_cover_images/9781337705028/9781337705028_smallCoverImage.gif)
Principles of Foundation Engineering (MindTap Cou…
Civil Engineering
ISBN:
9781337705028
Author:
Braja M. Das, Nagaratnam Sivakugan
Publisher:
Cengage Learning
![Structural Analysis](https://compass-isbn-assets.s3.amazonaws.com/isbn_cover_images/9781337630931/9781337630931_smallCoverImage.jpg)
![Structural Analysis (10th Edition)](https://www.bartleby.com/isbn_cover_images/9780134610672/9780134610672_smallCoverImage.gif)
Structural Analysis (10th Edition)
Civil Engineering
ISBN:
9780134610672
Author:
Russell C. Hibbeler
Publisher:
PEARSON
![Principles of Foundation Engineering (MindTap Cou…](https://www.bartleby.com/isbn_cover_images/9781337705028/9781337705028_smallCoverImage.gif)
Principles of Foundation Engineering (MindTap Cou…
Civil Engineering
ISBN:
9781337705028
Author:
Braja M. Das, Nagaratnam Sivakugan
Publisher:
Cengage Learning
![Fundamentals of Structural Analysis](https://www.bartleby.com/isbn_cover_images/9780073398006/9780073398006_smallCoverImage.gif)
Fundamentals of Structural Analysis
Civil Engineering
ISBN:
9780073398006
Author:
Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel Lanning
Publisher:
McGraw-Hill Education
![Sustainable Energy](https://www.bartleby.com/isbn_cover_images/9781337551663/9781337551663_smallCoverImage.gif)
![Traffic and Highway Engineering](https://www.bartleby.com/isbn_cover_images/9781305156241/9781305156241_smallCoverImage.jpg)
Traffic and Highway Engineering
Civil Engineering
ISBN:
9781305156241
Author:
Garber, Nicholas J.
Publisher:
Cengage Learning