Question

Explain in general in which area you would apply similarity concept along your career as
a mechanical engineer. How will it benefit you and your organisation.

Answer 1

When we want to analyse a big ship, submarine or aircraft we don’t start making one or sometimes it is not possible to test big structures so we make a smaller one and focus our attention on that smaller object known as prototype while the bigger structure of model is called model.Prototypes may not always be smaller than models.

Prototype is what we test before the final product is made. Prototypes are made and tested extensively under various scenarios and it helps engineers to predict possible outcomes and make necessary beforehand. Many design and material flaws can be identified before final production begins.Prototypes can be several types such as visual, functional or working prototype.

Fundamental concept we use while using the similarity concept is that their physics must be same for example while designing close duct flow we can not make analysis with open channel flow because forces involved are completely different. For close duct flow we use analysis using Reynolds number while for open channel flow we use froude number.

Similitude is also called similarity; it is of three types.

• Geometric similarity
• Kinematic Similarity
• Dynamic Similarity

As a mechanical engineer in analysis of big machines submarine I will be applying similarty analysis.

• Testing under different environments and understanding different outcomes. If prototypes fail it;s no problem new one will be made and mistakes wil;l be analysed however if final products fail it will be devastating.
• Similarity analysis will help in understanding geometries of prototype and model, velocity and acceleration , forces involved.
• Material behaviors will be studied under different temperatures which will help in understanding dimensional changes under extreme environmental conditions.

Similarity analysis helps in saving time and cost and gives ideas about the future so that changes are made for better efficiency and stability before the final product is made.