Working as a Mechanical Engineer

Working as a mechanical engineer can be a rewarding and fulfilling experience. Mechanical engineers work to design, build and analyze motor vehicles, aircraft, heating and cooling systems, watercraft, manufacturing plants, industrial equipment and machinery, robotics, medical devices, alternative energy and more.
Mechanical engineering has a long history, and mechanical engineers join a host of renowned inventors such as Archimedes (Golden Crown, Archimedes Screw, Claw of Archimedes), Henry Ford (Ford Motor Company), Rudolf Diesel (diesel engine) and Bill Nye the Science Guy (hydraulic pressure resonance suppressor used in the Boeing 747).

Financial

Mechanical engineering is a challenging, lucrative profession. The latest statistics from the U.S. Census (2013) report the mean annual salary for a mechanical engineer at $84,770. The Cockrell School of Engineering Salaries and Statistics report states the 2013 average starting for a mechanical engineer from this department was $69,044. By comparison, the U.S. Census reports a mean salary for all occupations in 2013 as $45,790.

Fields

Mechanical engineering is an incredibly broad field, and provides the engineer a number of different areas in which to work. Following is summary of the areas included in mechanical engineering.

Basic Engineering

Mechanical engineers deal with the mechanics of motion and the transfer of energy.

Applied Mechanics

Applied Mechanics looks at shock and vibration, dynamics and motion, and fracture and failure in components.

Fluids Engineering

There are mechanics involved in anything that flows — air, water, sand, oil, etc. Fluids engineers design and build systems that control or utilize flow, such as pumps, turbines, compressors, valves, pipelines and fluid systems in vehicles.

Heat Transfer

Heat moves in systems all around us, from computers, to automobiles, to ventilation systems. The field of heat transfer deals with combustion, power generation and transmission systems, process equipment, electronic devices, thermal controls in manufacturing, environmental controls, biotechnology, aerospace applications, transportation equipment and even cryogenics.

Bioengineering

Nearly every part of the human body may be described in mechanical terms. Bioengineering deals with artificial organs, biomechanics, biomaterials, bio-instrumentation, biotransport processes, human factors, medical devices, biomedical modeling and biological systems.

Tribology

Tribology deals with interacting surfaces in motion. It looks at friction, lubrication and wear. Any products which involves two surfaces rubbing against one another is the concern of a tribologist.

Energy Conversion

Our world is incredibly dependent on the conversion of energy into useful forms. A mechanical engineer is extremely important in this conversion.

Internal Combustion Engines

IC engines are not only used in automobiles, but are also used in aircrafts, marine vessels and even some stationary applications such as electric generators.

Fuels & Combustion Technologies

Some mechanical engineers specialize in fuels and combustion systems. In addition to working with combustion systems, they also deal with fuel processing, alternative fuels, fuel handling, transportation and storage.

Triga Reactor Core

Power Engineering

Mechanical engineers work in power engineering in the design and production of electricity-producing systems.

Energy Resources

In addition to working in the conversion of energy, mechanical engineers may also work in finding and developing new forms of energy.

Advanced Energy Systems

Mechanical engineers develop new energy systems such as power cycle devices, fuel cells, gas turbines and many others.

Solar Engineering

Mechanical engineers develop solar energy collectors and new and innovative ways to utilize solar energy.

Nuclear Engineering

Mechanical engineers may design and develop nuclear reactors and components, such as heat exchangers, radioactive waste systems and new fuel technologies.

Petroleum

The petroleum industry has been an important part of our lives for quite a while. Mechanical engineers work on oil and gas drilling and production, offshore and arctic operations, hydrocarbon processing, synfuels and coal technology, materials, equipment design and manufacture, fuel transport, new fuel technologies and pollution control.

Ocean, Offshore & Arctic Engineering

Much of our energy sources already comes from offshore sources. Mechanical engineers design and build ocean structures, systems, hyperbaric chambers, life support equipment, marine vehicles, submersibles and ROV's, propulsion systems, remote sensing systems, moorings and buoys, ship structures and ocean mining equipment.

Environment & Transportation

Getting from one place to another is something that affects every person every day of their lives. Mechanical engineers work to move us and our goods quickly and more efficiently. In addition, the effect that transportation, and other factors, have on the environment is something that concerns us all.

Aerospace & Automotive

Mechanical engineers design propulsion engines and structural component systems, crew and passenger accommodations and life support systems. They also develop the equipment used to build automotive, aircraft, marine and space vehicles.

Environmental Engineering

Environmental conditions normally deal with a mechanical process, the movement of heat, noise and pollutants through soil, water and air. Mechanical engineers can study the effects of these processes and work to reduce their impact on the environment.

Noise Control & Acoustics

Section of a wall of a RF anechoic chamber *
Photo by: prismatic

Sound is very much a mechanical phenomenon. It deals with the movement of vibrations through solids, liquids and gasses. A background in mechanical engineering can help to solve acoustical problems in noise control, industrial acoustics, and acoustic materials and structures.

Rail Transportation

Mechanical engineers design, build and maintain rail systems which help move people and goods every day. New developments are being applied to develop a new generation of locomotives for freight, passenger and transit services.

Solid Waste Processing

Solid waste processing is an important part of environmental protection. Mechanical engineers develop solid waste processing facilities, and work in areas related to recycling, resource recovery and waste-to-energy biomass conversion.

Manufacturing

Mechanical engineers are critical in making a product become reality.

Manufacturing Engineering

About half of mechanical engineers work for a company that makes something, whether it be consumer goods, transportation or industrial equipment. The work is as varied as the products that are produced.

Materials Handling Engineering

Handling materials can be challenging when the material is costly, exotic or dangerous. Some mechanical engineers specialize in materials handling, transportation, handling equipment or hazard control technologies.

Plant Engineering & Maintenance

Manufacturing plants often need to be updated. Mechanical engineers are crucial in this process.

Process Industries

A process engineer changes materials from one form to another so that they can be used in new and interesting ways. A mechanical engineer will design and build the machines that heat, cool, liquefy, harden or soften substances.

Textile Engineering

Textile companies seek out mechanical engineers in the design and production of the machines and plants that handle fabrics, weave or knit fabrics, manufacture apparel and handle the finished products.

Material sample after three-point bend testPhoto by: Sarah Grice

Materials & Structures

Mechanical engineers have to use a variety of different materials when making a product. The design and production of these materials is also an important process for a mechanical engineer.

Materials Engineering

A materials mechanical engineer focuses on properties of materials and their effect on design, fabrication, quality, and performance. They work to create materials which can be cast, forged, stamped, rolled, machined or welded.

Non-Destructive Evaluation

Nondestructive testing is necessary to determine the quality of a device without dismantling it. Mechanical engineers use x-rays, ultrasound, magnetic particle inspection, infrared and other techniques.

Pressure Vessels & Piping

Pressure vessels and piping are critical in many industries, and mechanical engineers develop materials that resist fatigue and fracture, plan the fabrication of equipment, perform inspections and tests, and design components.

Systems & Design

Most mechanical engineers work in the design and control of mechanical, electromechanical and fluid power systems. Design engineers take into account a truly wide number of factors in the course of their work, such as: product performance, cost, safety, manufacturability, serviceability, human factors, aesthetic appearance, durability, reliability, environmental impact and recyclability.

Dynamic Systems & Control

Dynamic systems need to be controlled. Typical applications of DSC include novel transducer designs, biomechanics at the cellular and human scale, dynamics and control of power and vehicle systems, and innovations in signal and information theory. These engineers are needed in a vast number of areas — aerospace and transportation, biomedical equipment, production machinery, energy and fluid power systems, expert systems and environmental systems.

Fluid Power Systems & Technology

 

An excavator, which employs hydraulic power systems, demolishes the old Experimental Sciences building to make way for new construction

Hydraulic and pneumatics systems are in everyday use. Mechanical engineers are needed to design and build these systems that could be used in automotive, aerospace, manufacturing, power industries and any situations that call for a flexible and precise application of power in large amounts.

Information Storage & Processing Systems

With the vast amounts of data that are stored in computer systems today, mechanical engineers are needed to design and manufacture the devices to store this data. They are normally involved in hard disk technologies, data storage and equipment, wear and lubrication in data storage devices, micro-sensors and controls.

Microelectromechanical Systems

Microelectromechanical systems combine computers with tiny mechanical devices such as sensors, valves, gears and actuators embedded in semiconductor chips. Mechanical engineers are needed for the design and development of these high-tech devices.

Conclusion

Mechanical engineers work in a variety of environments, for a variety of different types of companies. Companies throughout the state and nation need to employ engineers. To get an idea of the kinds of jobs available, one could search the American Society of Mechanical Engineers Career Center.

 

Dynamic Damping Control

Some time ago, we looked at the innards and working of Ducati’s latest semi –active suspension system called Ducati Skyhook Suspension (DSS). Today we look at one of its biggest competitor, BMW Motorcycle’s semi active technology. BMW has termed its semi-active suspension control Dynamic Damping Control (DDC). This technology was first introduced into BMW Motorrad bikes on the event of the BMW Motorrad Innovation Day 2011 and since then has been one of the favorites among the riders. However, BMW Motorcycles isn’t new to the field of semi-active suspension systems like Ducati. Back in 1986, BMW Motorrad had launched the Paralever swingarm , a technology that improved driveshaft rear suspension through the transfer of forces. Then in 1993, BMW introduced the Telelever which separated steering inputs from suspension and then in 2005, the Duolever was introduced that offered torsional rigidity through dual swingarms for the front wheels.
Also, BMW has not restricted the DDC technology to just 2 wheelers. Cars like the BMW M3 and M5 have been given the treatment of the DDC technology too. Coming to bikes, the DDC’s main philosophy is to adapt the suspension system to the requirements of motorcycle physics and integrating this in the relevant control systems. The DDC control system can be rightly viewed as a a step further in the evolution of the ESAII control that BMW introduced in 2004. The ESA technology allowed the the rider to adjust suspension elements at the push of a button which was a first in production motorcycles. The ESAII gave the additional control of spring rate variation.

Being the evolution of ESAII, the DDC reacts electronically to rider inputs in terms of braking, accelerating, and cornering on various road surfaces and further analyzes the parameters provided by sensors to set the correct level of damping at electrically-actuated proportional damping valves. In DDC, the rider gets 3 riding modes- “Comfort,” “Normal,” and “Sport”, each having its individual characteristic control maps. Let us examine how the DDC comes into life right from the point when you get on the bike. When the ignition key is activated, a complete system check is performed from ECU to the ABS module to the DTC control, spring travel sensors and DDC control unit. When you set off, the front and the rear damper valves are actuated only marginally. Now, when you leave the city limits and go to highway cruising, the rear damper valve is actuated more strongly due to increased dynamic wheel load distribution and in the drive torque.

When you are cornering, things get slightly complicated. Initially both the valves are actuated more strongly with increasing inclination until it reaches the vertex. When the rider comes to the original position between 2 corners, the actuation of the two damping valves constantly drops to the original power level with decreasing inclination. Again when the bike dips into the next corner, the loop begins. The control flow takes place from the DTC sensor box to the DDC control unit and then to the valve actuators in the spring dampers. Finally, the valve controls get de-activated when the motorcycle is brought to a stop.

CHASSIS

A chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame (on which the body is mounted) with the wheels and machinery.

Vehicles

  1950s Jeep FC cowl and chassis for others to convert into finished vehicles

In the case of vehicles, the term chassis means the frame plus the "running gear" like engine, transmission, driveshaft, differential, and suspension. A body (sometimes referred to as "coachwork"), which is usually not necessary for integrity of the structure, is built on the chassis to complete the vehicle. For commercial vehicles chassis consists of an assembly of all the essential parts of a truck (without the body) to be ready for operation on the road.^[1] The design of a pleasure car chassis will be different than one for commercial vehicles because of the heavier loads and constant work use.^[2] Commercial vehicle manufacturers sell “chassis only”, “cowl and chassis”, as well as "chassis cab" versions that can be outfitted with specialized bodies. These include motor homes, fire engines, ambulances, box trucks, etc  
.
In particular applications, such as school buses, a government agency like National Highway Traffic Safety Administration (NHTSA) in the U.S. defines the design standards of chassis and body conversions.^[3]
An armoured fighting vehicle's hull^[4] serves as the chassis and comprises the bottom part of the AFV that includes the tracks, engine, driver's seat, and crew compartment. This describes the lower hull, although common usage of might include the upper hull to mean the AFV without the turret. The hull serves as a basis for platforms on tanks, armoured personnel carriers, combat engineering vehicles, etc.

Ferrari 599 GTB Fiorano

The 599 GTB Fiorano (internal code F141) is an Italian gran turismo produced by Ferrari. It was the brand's two-seat flagship, replacing the 575 M Maranello in 2006 as a 2007 model, but was replaced for the 2013 model year by the F12 Berlinetta.
Styled by Pininfarina under the direction of Ferrari's Frank Stephenson, the 599 GTB debuted at the Geneva Motor Show in February 2006. It is named for its total engine displacement (5999 cc), Gran Turismo Berlinetta nature, and the Fiorano Circuit test track used by Ferrari.

Drive train

The Tipo F140C 6.0 L (5999 cc) V12 engine produces a maximum 620 PS (456 kW; 612 hp), making it the most powerful series production Ferrari road car of the time. This is one of the few engines whose output exceeds 100 hp per liter of displacement without any sort of forced-induction mechanism such as supercharging or turbocharging. Its 608 N·m (448 ft·lbf) of torque will also be a new record for Ferrari's GT cars. Most of the modifications to the engine were done to allow it to fit in the Fiorano's engine bay (the original Enzo version could be taller as it would not block forward vision due to its mid-mounted position).^[2]

A 599 GTB Fioriano in Paris, France

A traditional 6-speed manual transmission as well as Ferrari's 6-speed called "F1 SuperFast" is offered. Reviewers of the car have mentioned that the MagneRide suspension gives the 599 a very comfortable ride but allows it to handle well at the same time..^{[citation needed]}
The Fiorano also sees the debut of Ferrari's new traction control system, F1-Trac.

Performance

Performance claimed by Ferrari.

• 0-100 km/h (62 mph) in 3.7 seconds^[3]
• 0-200 km/h (124 mph) in 11.0 seconds^[4]
• Top speed: over 330 km/h (205 mph)

Engine Installation	Type	Make	Bore/Stroke	Compression Ratio	Valve Gear	Power	Torque	Red Line	Power-to-Weight Ratio
Front Longitudinal	V12, 5999 cc, petrol	Aluminum Head and Block	92.0/75.2 mm	11.2:1	4 per cylinder	620 PS (456 kW; 612 hp) @ 7600 rpm	608 N·m (448 lb·ft) @ 5600 rpm	8400 rpm	367 PS (270 kW; 362 hp) per tonne

How Two-stroke Engines Work

If you have read How Car Engines Work and How Diesel Engines Work, then you are familiar with the two types of engines found in nearly every car and truck on the road today. Both gasoline and diesel automotive engines are classified as four-stroke reciprocating internal-combustion engines.
There is a third type of engine,­ known as a two-stroke engine, that is commonly found in lower-power applications. Some of the devices that might have a two-stroke engine include:

• Lawn and garden equipment (chain saws, leaf blowers, trimmers)
• Dirt bikes
• Mopeds
• Jet skis
• Small outboard motors
• Radio-controlled model planes

In this article, you'll learn all about the two-stroke engine: how it works, why it might be used and what ­makes it different from regular car and diesel engines.

5 AXIS MALLING

5-Axis machines are the most advanced CNC (computer numeric controlled) milling machines, adding two more axes in addition to the three normal axes (XYZ). 5-Axis milling machines also have a B and C axis, allowing the horizontally mounted workpiece to be rotated, essentially allowing asymmetric and eccentric turning. The fifth axis controls the tilt of the tool itself. When all of these axes are used in conjunction with each other, a competent and experienced machinist can produce extremely complicated geometries with very high precision.

Many industries today, especially the high-tech, precision-dependent worlds of optical equipment, medical devices, satellites, aircraft, and aerospace, are turning to 5-Axis machining as a means to speed manufacturing ability and increase repeatable accuracy. The ability to machine complex shapes, undercuts and difficult angles in a single setup reduces tooling cost and labor time, resulting in much better precision along with lower cost per part and the ability to maintain parts conformity throughout the part run and in future runs.

Anti-Lock Braking System (ABS) in Motorcycles

TVS has already made their ability by introducing Apache 180 with ABS. ABS in not a new concept for four wheeler and two wheeler as well. In 1988, BMW introduced the first motorcycle with an electronic-hydraulic ABS: the BMW K100. Honda followed suit in 1992 with the launch of its first motorcycle ABS on the ST1100 Pan European. In 2007, Suzuki launched its GSF1200SA (Bandit) with an ABS.

In 2005, Harley-Davidson began offering ABS as an option for police bikes. In 2008, ABS became a factory-installed option on all Harley-Davidson Touring motorcycles and standard equipment on select models. Now let us enlighten how ABS works on bikes.

Skidding Mechanism

Skidding of a vehicle leads to disaster in many cases. Skidding starts when force applied by driver on the brake lever is more than the required. Skidding results when friction in brakes become more than the friction exists between tyre and road surface. That means wheel gets locked and start skidding on road surface. Less force leads to poor braking and more force leads to skidding. So to avoid the skidding of vehicle, the braking force should remain in limit.
In normal bikes, the brake lever is directly connected with calliper. The force applied by the driver on lever is directly exerted on calliper & disc without any interrupt. In the case of ABS, this braking force is exerted through ECU and Hydraulic valve.
The ABS prevents the wheels from locking during braking. It does this by constantly measuring the individual wheel speeds and comparing them with the wheel speeds predicted by the system. This speed measurement is done by individual speed sensors.
If, during braking, the measured wheel speed deviates from the system‘s predicted wheel speed, the ABS controller takes over, correcting the brake force to keep the wheel at the optimum slip level and so achieving the highest possible deceleration rate.
This is carried out separately for each wheel. Controller is nothing but an ECU with appropriate programming. This program avoids the rotational speed of wheel to become zero (Locking). This is done by temporary releasing the brake force by shutting off the valve in oil reservoir.
The ECU constantly monitors the rotation speed of each wheel. When it detect that any number of wheel are rotating slower than the other (this condition will bring the tyre to lock), it moves the valves to decrease the pressure on the braking circuit, effectively reduce the braking force on that wheel.
The wheels turn faster and when they turn too fast, the force is reapplied. This process is repeated continuously, and this is causes characteristic pulsing feel through the brake pedal.

Figure show major parts of Antilock-Braking System. Basic of antilock braking system consists of three major parts;

1. Electronic Speed Sensor: This sensor will measure the wheel velocity and vehicle acceleration. LOCATION: On wheel Hub
2. Toothed Disc: It helps the speed sensor to read the speed of wheel. LOCATION: With Brake Disc
3. Electrical Control Unit (ECU). ECU is a microprocessor based system contains program. LOCATION: Under the Driver’s Seat
4. Electrically Controller Valve. This controller valve will control the pressure in a brake cylinder. LOCATION: With ECU

The following are the 3 major benefits of ABS

1. Stopping Distance

 

As the braking force is controlled and applied electronically, the stopping distance reduces considerably in comparison with normal bike.

2. Sudden Braking

In the case of ABS, the braking is intermittent in nature. So vehicle remains easily steerable during braking also. Below figure shows the comparison of normal bike and ABS bike at sudden braking.

3. Braking on Slippery surface

Most of the riders must have experienced this condition with their bikes and also know the results. ABS provides equal distribution of braking force on each wheel and provides straight line stopping of vehicle.

Some Interesting Facts about ABS

Donovan Green, United States, Department of Transportation had performed some experiments on bikes with and without ABS in 2006. Following bike were selected by him for his test.

• 2002 Honda VFR 800 with ABS
• 2002 BMW F650 with ABS
• 2002 BMW R 1150R with ABS
• 2002 BMW R 1150R without ABS
• 2004 Yamaha FJR1300 with ABS
• 2004 Yamaha FJR1300 without ABS

He had performed two types of tests: 1. Dry Surface Tests 2. Wet Surface Tests. Following are the results of his experiments.

Dry Surface Tests

On the ABS-equipped motorcycles, the operator was tasked with braking sufficiently to assure the operation of the ABS. The measured stopping distance values were corrected to compare data from the speeds of 48 km/h and 128 km/h, except for the BMW F650 data, which was corrected to 48 km/h and 117 km/h, the latter figure limited by that model’s top speed of 157 km/h (i.e. 75% of 157 km/h).
In the ABS-enabled mode, for each load/speed/brake combination, the stopping distances were very consistent from one run to another. In this mode, the braking force was applied in a controlled and consistent manner by the ABS mechanism. With the exception of having to react to the possibility of the rear wheel becoming airborne under high deceleration, the rider did not require significant experience or special skill in order to achieve a high level of performance.
In the ABS-disabled mode, the stopping distances were less consistent because the rider while modulating the brake force, had to deal with many additional variables at the same time. Up to six runs were allowed for the rider to become familiar with the motorcycle’s behaviour and to obtain the best stopping distance.
Test results from non-ABS motorcycles were noticeably more sensitive to rider performance variability.
Despite being compared to the best stopping distances without ABS, the average results with ABS provided an overall reduction in stopping distance of 5%.
The stopping distance reduction was more significant when the motorcycle was loaded (averaging 7%). The greatest stopping distance reduction (averaging 17%) was observed when only the rear foot pedal was applied to stop the motorcycle from 128 km/h.

Wet Surface Tests

The original test procedure called for wet surface braking tests to be conducted at 48 and 128 km/h. However, for safety and stability reasons, all low-friction surface tests were performed in a straight-line maneuver, from an initial speed of 48 km/h. The tests were repeated with and without ABS. The test track was wetted by a water truck, and the wetting procedure was repeated every three stops.
With ABS-equipped motorcycles, the rider was instructed to brake sufficiently to assure that the ABS was fully cycling by applying as much force as necessary to the brake control device (no restrictions on force application).
The front and rear wheel brakes were operated simultaneously when the initial test speed was reached and then were operated individually when the front wheel and rear wheel were tested separately. During braking, the engine remained disconnected from the drive train.
A steering operation was allowed to keep or correct the running direction of the motorcycle during the test. Below vehicle speeds of 10 km/h, wheel locking was permitted.
For motorcycles not equipped with ABS, the test procedure was the same except that the rider was instructed to apply as much force as required on the brake control device in order to get the shortest stopping distance without losing vehicle control or having any wheel lockup above a speed of 10 km/h.
As with the dry surface tests, practically no learning process was required for the operator to achieve the best performance with the operation of ABS. In the ABS-disabled mode, the stopping distances improved as the rider became more familiar and comfortable with the braking system.
On the wet surface, the overall average stopping performance with ABS improved on the best non-ABS stopping distance by 5.0%. The stopping distance reduction with ABS was more significant when both brakes were applied, with an overall improvement averaging 10.8% over the best stops without ABS.
The greatest stopping distance reduction with the use of ABS was observed when the motorcycle was loaded and both brakes were applied, averaging a 15.5% improvement over the best stops without ABS.

In general, the test results demonstrated an improvement in braking performance with the use of ABS, whether braking on a dry or wet surface even compared with the best stops obtained without ABS.