Turbine and its Classification

Turbine

Turbine is a device that extracts energy from a fluid (converts the energy held by the fluid to mechanical energy)

• Pumps are devices that add energy to the fluid (e.g. pumps, fans, blowers, and compressors)  
• Hydroelectric power is the most remarkable development pertaining to the exploitation of water resources throughout the world.
• Hydroelectric power is developed by hydraulic turbines which are hydraulic machines.
• Turbines convert hydraulic energy or hydro-potential into mechanical energy.
• The mechanical energy developed by turbines is used to run electric generators coupled to the shaft of turbines.
• Hydroelectric power is the cheapest source of power generation.

  Classification of turbines

 1: On the basis of hydraulic action or type of energy at the inlet

•  Impulse Turbine (Pelton Wheel)
•  Reaction Turbine (Francis Turbine)

 2: On the basis of the direction of flow through the runner

• Tangential flow turbine (Pelton)
• Radial flow turbine (Francis )
• Axial Flow Turbine (Kaplan)
• Mixed flow turbine (Modern Francis)  

3: On the basis of the head of water

• High head turbine (Pelton, H>250m)
• Medium head turbine (modern Francis, 60-250m)
•  Low head turbine (Kaplan, <60m)

4: On the basis of specific speed Ns of the turbine

•  Low specific speed (Pelton, 10-35)
•  Medium (Francis, 60-400)
• High specific speed (Kaplan, 300-1000)  

Why Are Tires Black? The Science Behind Rubber Tires

Have you ever wondered why tires are black, even though natural rubber is white? The answer lies in the addition of an ingredient called carbon black, which transforms the color of rubber and significantly improves its performance.

The Natural Color of Rubber

Rubber, in its natural state, is actually milky white. This may come as a surprise since we're so accustomed to seeing black tires on our vehicles. So why aren't tires white?

The Role of Carbon Black

In the early 19th century, manufacturers discovered that adding carbon black to rubber produced a much stronger and longer-lasting tire. Here’s how carbon black works:

• Reinforcing Filler: Carbon black acts as a reinforcing filler in rubber, which increases the durability and strength of the tire. This means the tire can withstand more wear and tear over time.
• Heat Conduction: Tires generate a lot of heat while driving, especially in the tread and belt areas. Carbon black helps conduct heat away from these areas, reducing the likelihood of damage and extending the tire’s lifespan.

Why Are Tires Black?

In summary, tires are black because carbon black is added during the manufacturing process. This ingredient not only changes the color of the rubber but also makes the tires stronger, more durable, and longer-lasting.

So, the next time you look at your car’s tires, remember that their black color is a key part of what makes them safe and reliable on the road!

Casting and Forging difference

Casting vs Forging

Casting:

Casting is a process in which molten metal flows by gravity or other force into a mold where it solidifies in the shape of the mold cavity

• The term casting also applies to the part made in the process
• Steps in casting seem simple:

1. Melt the metal
2. Pour it into a mold
3. Let it freeze

Advantages of Casting:

•       Can create complex part geometries
•       Can create both external and internal shapes.
•       Some casting processes are net shape*; others are near net shape.
•       Can produce very large parts.
•       Some casting methods are suited to mass production.
•       Suitable for any metal that can be heated to a liquid.

  Disadvantages of Casting:     

•       Limitations on mechanical properties.
•       Poor dimensional accuracy and surface finish for some processes; e.g., sand casting.
•       Safety hazards to workers due to hot molten metals.
•       Environmental problems.

Forging:

                Deformation process in which work is compressed between two dies using either impact or gradual pressure to form the part.

•        Oldest of the metal forming operations, dating from about 5000 BC.
•        Components: engine crankshafts, connecting rods, gears, aircraft structural components, jet engine turbine parts. 
•         Also, basic metals industries use forging to establish a basic form of large parts that are subsequently machined to final shape and size.  
• 
  

Classification of Forging Operations:

                 1. Hot or warm forging:

                               Most common, due to the significant deformation and the need to reduce strength and increase the ductility of work metal.

               2. Cold forging:   

                      Advantage: increased strength that results from strain hardening. Cold forging is generally preferred when the metal is already a soft metal, like aluminum.  

Advantages of Forging:

• It produces a tougher product compare to other.
• The product made by forging has high impact or tensile strength.

Heat Transfer

Difference between Heat and Temperature

• Temperature is a measure of the amount of energy possessed by the molecules of a substance. It is a measure of hotness and coldness.
• Heat, on the other hand, is energy in transit. Heat is a form of energy which transfers from one system to another due to the temperature difference. 

Modern theory of Heat transfer

The kinetic energy of molecules of a substance is directly proportional to the absolute temperature.
The kinetic energy of molecules is sum of

1. Vibrational Energy
2. Rotational Energy
3. Translational Energy

Application Areas of Heat Transfer

Basic law of Thermodynamics

1) The First Law of Thermodynamics:

         Energy can not be created nor destroyed but can be changed from one form to another. It is also known as the law of conservation of energy.

2) The Second Law of Thermodynamics:

The change in the entropy in the universe can never be negative.

3) The Third Law of Thermodynamics:

     The entropy of a system approaches zero as the temperature approaches absolute zero.

4) The Zeroth Law:

    If two systems are in thermal equilibrium with the third system, they are equilibrium with each other.

Modes of Heat Transfer

1) Conduction:

    An energy transfer across a system boundary due to a temperature difference by the mechanism of molecular interaction.

Conduction is a mode of heat transfer that occurs in solid and fluids when there is no bulk movement of fluid.  

Fourier’s law of heat conduction: 
      The law of heat conduction, also known as Fourier's law, states that the time rate of heat transfer through a material is proportional to the negative gradient in the temperature and to the area, at right angles to that gradient, through which the heat flows
                               q = -kAdT/dx

2) Convection: 

The transfer of heat from one place to another by the movement of fluids. Convection is usually the dominant form of heat transfer in liquids and gases

Newton’s law of cooling:

                              q = hA (Tw - T∞)

3) Radiation:

Heat transfer through radiation takes place in form of electromagnetic waves mainly in the infrared region.Radiation emitted by a body is a consequence of thermal agitation of its composing molecules.

Radiation required no medium for heat transfer.

Stefan-Boltzmann Law:

An ideal thermal radiator, or blackbody, will emit energy at a rate proportional to the fourth power of the absolute temperature of the body and directly proportional to its surface area

                              q emitted = σAT 4

                        

Welcome to my First Blog Post

Welcome to ENGINEERING WORLD!

Hello, and welcome to my blog, ENGINEERING WORLD! I’m thrilled to share my passion for engineering with you. As an engineer myself, I’ve always been fascinated by how engineering shapes the world around us. Whether it’s the buildings we live in, the vehicles we drive, or the technology we use every day, engineering is at the heart of it all.

What Is Engineering?

Engineering is a discipline that has existed since ancient times, evolving as humans devised essential inventions like the lever, the wheel, and the pulley. These early innovations embody the essence of engineering, defined as the application of science and mathematics to solve problems and create useful objects or systems.

When you look around, you'll see engineering applications everywhere. From the buildings we live and work in to the cars we drive and the smartphones we use, engineering is all around us. The word "engineering" itself comes from "engine," a term historically used to describe a device or machine, particularly one used for war. Today, engineering spans a vast range of fields, each contributing to the advancement of society in unique ways.

The Impact of Engineering on Our Lives

Imagine life without electricity, transportation, or even the wheel—an invention that drastically changed the course of human history by reducing the friction that made movement difficult. Engineering has been the driving force behind countless inventions that have shaped the modern world, making it possible for us to live more comfortably, efficiently, and safely.

Buildings, bridges, dams, cars, planes, computers, and smartphones are all products of engineering. These innovations have become so integrated into our daily lives that it's hard to imagine living without them. Engineering doesn’t just solve problems; it transforms them into opportunities for improvement and innovation.

The Diverse World of Engineering

Engineering is a vast and diverse field, encompassing numerous specialties. Some of the most well-known branches include:

• Mechanical Engineering: Focuses on the design and manufacturing of mechanical systems, from engines to heating systems.
• Electrical Engineering: Deals with the study and application of electricity, electronics, and electromagnetism.
• Civil Engineering: Involves the design, construction, and maintenance of infrastructure like roads, bridges, and buildings.
• Chemical Engineering: Combines physical sciences with life sciences to produce chemicals, materials, and energy.
• Software Engineering: Concerned with designing, developing, and maintaining software systems.

Each of these fields plays a crucial role in making the world a better place. Engineers work tirelessly to find solutions to the challenges we face, from developing renewable energy sources to creating sustainable infrastructure for future generations.

Conclusion

Engineering is all around us, silently shaping our world and improving our lives in countless ways. As I continue to explore this exciting field, I hope to share insights and discoveries that will inspire you to appreciate the incredible impact engineering has on our daily lives. Stay tuned for more posts, and join me on this journey through the ENGINEERING WORLD!