Models

Question 1

What are the advantages of numerical models?

Answer 1

• Often the cheap option
• Relatively fast
• Computer models produce pretty pictures

Question 2

Why are physical models still needed? (advantages)

Answer 2

• not all equations describing fluid motion can be mathematically solved
• no analytical solution for complex, turbelent flows exist, always must make simplifications in terms of the flow characteristics, roughness etc

Question 3

when are physical models used?

Answer 3

• Validation and calibration of numerical models(hybrid modelling)
• Testing of numerical model results
• cost saving for projects
• Providing design guidelines for hydraulic engineers (design charts such as the moody diagram)
• advancing fundamental understading of complex fluid processes
• when failure of a structure could be a catastrophe

Question 4

which designs are physical models used?

Answer 4

• hydrualic structures e.g breakwaters, spillways, weirs, energy dissipaters
• rivers, estuaries
• ships, tall buildings, flow through pumps and pump intakes