Apakah yang dimaksud dengan Mesin ?

Apakah yang dimaksud dengan mesin ?
Pada blog ini akan dijelaskan mengenai mesin mobil, terutama mesin bensin. Apa yang dimaksud dengan engine atau mesin, definisi engine sampai saat ini juga masih membingungkan dan masih diperdebatkan. Namun konsep dasar engine adalah “ suatu benda yang bisa menggerakan sesuatu dengan cara menghasilkan tenaga yang didapat dari alam seperti api, angin atau benda elektrik

Mobil Listrik

BANDUNG, KOMPAS.com — PT Pindad memamerkan motor listrik buatannya dalam ajang RITech Expo pada Rabu (8/8/2012) di Sasana Budaya Ganesha, Bandung, Jawa Barat. Dalam pameran, motor dipasang pada mobil listrik sehingga bisa diuji keandalannya.

Motor listrik yang dibuat adalah jenis Brushless DC Motor. Motor listrik ini memiliki daya 50 KW, jauh dari motor listrik umumnya yang hanya berdaya 15 KW. Dengan pembuatan motor ini, Indonesia merupakan negara pertama yang membuat motor listrik 50 KW.

Andri Setiyoso, Chief Engineer untuk Mesin Listrik di PT Pindad, mengungkapkan bahwa pengembangan motor listrik ini bertujuan membantu merealisasikan produksi mobil listrik yang ramah lingkungan. "Dengan memproduksi sendiri, harga motor bisa lebih murah daripada harus mengimpor. Harganya bisa Rp 15-Rp 20 juta lebih murah. Apalagi mendatangkan motor listrik dari luar itu lebih sulit, terutama kalau sudah produksi," ungkap Andri.

Sena Maulana, Product Development Kendaraan Tempur di PT Pindad, mengungkapkan bahwa semua mobil listrik yang dikembangkan di Indonesia masih menggunakan baterai dan motor berupa kit yang dibeli dari Amerika. "Dengan mengembangkan sendiri, Pindad ke depan orientasinya justru menjual kit motor listrik ini ke industri mobil yang kita miliki," papar Sena kepada Kompas.com saat ditemui hari ini di Bandung.

Sena pun menuturkan, pengembangan motor listrik juga bertujuan mengenalkan kepada masyarakat bahwa teknologi mobil listrik sebenarnya cukup mudah. Motor listrik tak membutuhkan banyak maintenance seperti motor konvensional.

Sementara itu, Andri menjelaskan, "Untuk kualitas, sebenarnya kan PT Pindad bukan pertama kali ini mengembangkan motor. Sebelumnya kita juga mengembangkan motor untuk KKRL dan hasilnya bisa bersaing dengan yang impor."

Menurut Andri, beberapa kendala untuk membuat motor listrik saat ini masih perlu dipecahkan, misalnya soal material. Ia berharap, ke depan, Indonesia bisa menghasilkan silicon steel, magnet, dan tembaga untuk mendukung pembuatan motor listrik ini. 

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How Airplanes Work

Human flight has become a tired fact of modern life. At any given moment, roughly 5,000 airplanes crisscross the skies above the United States alone, amounting to an estimated 64 million commercial and private takeoffs every year [source: NATCA]. Consider the rest of the world's flight activity, and the grand total is incalculable.

It is easy to take the physics of flight for granted, as well as the ways in which we exploit them to achieve flight. We often glimpse a plane in the sky with no greater understanding of the principles involved than a caveman.

How do these heavy machines take to the air? To answer that question, we have to enter the world of fluid mechanics.

Physicists classify both liquids and gases as fluids, based on how they flow. Even though air, water and pancake syrup may seem like very different substances, they all conform to the same set of mathematical relationships. In fact, basic aerodynamic tests are sometimes performed underwater. To put it simply, a salmon essentially flies through the sea, and a pelican swims through the air.

The core of the matter is this: Even a clear sky isn't empty. Our atmosphere is a massive fluid layer, and the right application of physics makes it possible for humans to traverse it.

In this article, we'll walk through the basic principles of aviation and the various forces at work in any given flight.

how to steam generators work

Heat Exchange

• Steam generators are used to harness energy liberated as heat in a wide variety of processes and convert it into a form which is more useful, such as mechanical and electrical energy. The heat used is typically produced intentionally for the production of electricity or is captured as a byproduct of some other industrial process. The immediate source of the heat is usually dirty, such as the radioactive fuel in a nuclear power plant, so the first step of steam power generation is to transfer that heat into clean water with a heat exchanger. This is done by having the heat source elevate the temperature of an exchange medium, such as an oil, that is circulated in a closed circuit. The oil in turn heats a water reservoir without contaminating it.

Steam Generation

• The hot oil is circulated through a water bath to generate steam. There are several different geometrical schemes for doing this, but the principle remains the same. The heating liquid is diverted into many smaller pipes to increase its surface contact with the water and facilitate rapid heat exchange and steam production. The steam produced in modern nuclear and coal power plants is often at supercritical conditions, or above the critical point in water's phase diagram (374 degrees Celsius and 22 MPa).

Conversion of Heat to Electricity

• Supercritical steam is overloaded with energy. Steam's energy is converted into mechanical energy by forcing it through a steam turbine. The high pressure of the steam pushes on the many angled blades of the turbine, causing the shaft to rotate. This mechanical energy is converted to electricity by using the power form the rotating shaft to turn an electrical generator. The turbine being built in the image may generate up to 65 megawatts of electricity.

Read more: How Steam Generators Work | eHow.com http://www.ehow.com/how-does_5095506_steam-generators-work.html#ixzz22BbpQWwE

how to diesel engines work

O­ne of the most popular HowStuffWorks articles is How Car Engines Work, which explains the basic principles behind internal combustion, discusses the four-stroke cycle and talks about all of the subsystems that help your car's engine to do its job. For a long time after we published that article, one of the most common questions asked (and one of the most frequent suggestions made in the suggestion box) was, "What is the difference between a gasoline and a diesel engine?"

Diesel's story actually begins with the invention of the gasoline engine. Nikolaus August Otto had invented and patented the gasoline engine by 1876. This invention used the four-stroke combustion principle, also known as the "Otto Cycle," and it's the basic premise for most car engines today. In its early stage, the gasoline engine wasn't very efficient, and other major methods of transportation such as the steam engine fared poorly as well. Only about 10 percent of the fuel used in these types of engines actually moved a vehicle. The rest of the fuel simply produced useless heat.

I­n 1878, Rudolf Diesel was attending the Polytechnic High School of Germany (the equivalent of an engineering college) when he learned about the low efficiency of gasoline and steam engines. This disturbing information inspired him to create an engine with a higher efficiency, and he devoted much of his time to developing a "Combustion Power Engine." By 1892 Diesel had obtained a patent for what we now call the diesel engine.

­If diesel engines are so efficient, why don't we use them more often? You might see the words "diesel engine" and think of big, hefty cargo trucks spewing out black, sooty smoke and creating a loud clattering noise. This negative image of diesel trucks and engines has made diesel less attractive to casual drivers in the United States -- although diesel is great for hauling large shipments over long distances, it hasn't been the best choice for everyday commuters. This is starting to change, however, as people are improving the diesel engine to make it cleaner and less noisy.

If you haven't already done so, you'll probably want to read How Car Engines Work first, to get a feel for the basics of internal combustion. But hurry back -- in this article, we unlock the secrets of the diesel engine and learn about some new advancements.