Studi Eksperimental Dan Analisis Perpindahan Panas Konveksi Alamiah Pada Suatu Rongga Dengan Variasi Derajat Kevakuman

Mulyono, Mulyono (2005) Studi Eksperimental Dan Analisis Perpindahan Panas Konveksi Alamiah Pada Suatu Rongga Dengan Variasi Derajat Kevakuman. Masters thesis, Institut Teknologi Sepuluh Nopember.

Text 2101202006-Master_Thesis.pdf - Accepted Version Download (43MB)

Abstract

Dalam dunia industri, material isolasi senng digunakan untuk mempertahankan temperatur zat pacta keadaan dingin atau panas. Disamping mahal dan tebal ukuran penggunaan material isolasi terkadang dipandang kurang praktis. Untuk menggantikan fungsi material isolasi sering digunakan rongga
udara bertekanan rendah a tau vakum. Membuat derajat kevakuman 100 % pacta rongga udara tidaklah mudah. Biasanya masih adanya udara di dalam rongga akan mengakibatkan terjadinya perpindahan panas konveksi alami (natural convection) antara kedua permukaan pembentuk rongga tersebut. Koeffisien perpindahan panas konveksi (h) pacta suatu rongga selain dipengaruhi oleh perbedaan temperatur juga dipengaruhi oleh geometri rongga, orientasi dari rongga dan sifat�sifat yang dimiliki oleh fluida , antara lain : tekanan, temperatur, massa jenis, konduktifitas dan viskositas.
Pennasalahan yang timbul dalam penelitian ini adalah bagaimanakah pengaruh variasi derajat kevakuman dan ratio rongga terhadap laju perpindahan Panas konveksi alamiah pacta suatu rongga. Tujuan penelitian ini adalah untuk mendapatkan harga tekanan Vakum yang sesuai sebagai isolator dalam suatu rongga. Sedangkan manfaat dalam studi ini adalah untuk menghambat laju perpindahan panas antara sistem terhadap media sekelilingnya.
Dari penelitian ini diperoleh hasil bahwa dengan derajat kevakuman -60 em Hg dan L = 5.96 diperoleh harga laju perpindahan Panas konveksi alamiah 8 lebih rendah dibandingkan dengan derajat kevakuman -20 em Hg dan - 40 em
Hg. Ini memberikan arti bahwa derajat kevakuman - 60 em Hg mempunyai hambatan tennallebih besar (isolator) dibandingkan dengan derajat kevakuman - 20 em Hg dan -40 em Hg.
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This paper reports on a study aimed at finding the appropriate degree of vacuum pressure which effectively works as insulator. In the world of industry, insulation materials are often utilized to maintain the temperature, either low or high. However, since the insulation materials often need to be thick, thus, costly, they are frequently deemed impractical. Therefore, in the attempt to replace the insulation materials, a cavity with low vacuum pressure is opted for. Yet, to attain a total (100%) air-free cavity is not an easy task. Such, the cavity usually still bears some amount of air pressure which results in natural heat convection through the two surfaces making up the cavity.
The transfer coefficient of natural heat convection (h) is influenced by some factors, such as, the temperature difference, geometry of the cavity, cavity orientation, and characteristics of the fluid, for instance, its pressure, temperature, conductivity, specific gravity (density), and viscosity.
The purpose of the study is to find answers to the following question:
"How do vacuum pressure variation and cavity ratio affect the rate of natural heat convection through the a cavity?" Pertinent to the question, the study was aimed to find the appropriate value ofthe vacuum pressure which can function well as an insulator. This study is significant in the attempt to lower down the rate of heat transfer taking place in a system vis-a-vis the surrounding media. The study found out that the degree of emptiness of -60 em Hg and L =5.96, results in a lower rate of heat transfer compared with -20 em Hg and- 5 40 em Hg. This means that the vacuum pressure of -60 ern Hg bears a bigger thermal resistance than the -20 em Hg and -40 em Hg do.

Item Type:	Thesis (Masters)
Additional Information:	RTM 621.402 2 Mul s 2005
Uncontrolled Keywords:	Derajal Kevakuman, rongga, laju perpindahan panas konveksi alamiah, aspek ratio rongga
Subjects:	Q Science > QC Physics > QC320 Heat transfer
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21101-(S2) Master Thesis
Depositing User:	- Davi Wah
Date Deposited:	10 Nov 2023 08:56
Last Modified:	10 Nov 2023 08:56
URI:	http://repository.its.ac.id/id/eprint/105085

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