Öz
Birçok askerî sistem ve silahlar elektronik ekipmanlar
içermektedir. Bu ekipmanlar çalışmaları sırasında yüksek sıcaklıklara
çıkabilmektedir. Bu durum, eğer bu ekipmanlar güvenli çalışma sıcaklıklarına
soğutulmaz ise, içerdikleri elektronik devre elemanlarının yanmasına ve tüm askerî
sistemin çalışamamasına sebep olabilmektedir. Bundan dolayı, bu çalışmada askerî
bir sistemin içerdiği elektronik devre elemanlarının daha etkin bir şekilde
soğutulması ele alınmıştır. Bu amaçla, devre elemanlarını temsil eden bir blok
şeklinde cismin, askerî sistemlerin ana kartlarının bulunduğu hacmi temsil eden
bir kanal hacmi içerisine yerleştirildiği düşünülmüştür. Yüksek sıcaklıklara
çıkan bu bloğun, çapraz ve jet akışın birlikte kullanımı ile etkin olarak
soğutulduğu varsayılmıştır. Bu amaçla, kanal girişinde sabit hızda bir hava
girişi yapılarak, çapraz akış şartları sağlanmıştır. Kanal üst yüzeyinde
bulunan bir delikten ise, yine sabit hızda hava girişi yapılmak suretiyle
çarpan jet akış koşulları sağlanmıştır. Analizler, çapraz akışın hava giriş
koşulları baz alınarak hesaplanan Reynolds sayısının 500, 1000, 1500 ve 2000
değerleri için laminer olarak yapılmıştır. Bu Reynolds sayılarında, jet giriş
hava hızının, çapraz akış giriş hava hızına oranı (Vj/Uk) değiştirilerek
simülasyonlar tekrarlanmıştır. Sonuç olarak, Reynolds sayısının artışı ile blok
yüzeyinden gerçekleşen ısı transferinin arttığı belirlenmiştir. Vj/Uk
oranının artması ile ise ikincil jet akışın genel akış yapısı üzerindeki etkisi
artmaktadır. Vj/Uk
oranı arttıkça, akışkan blok yüzeylerine doğru baskılanmakta ve blok
yüzeylerinde oluşan hız ve ısıl sınır tabakalarının bozulmasına sebep
olmaktadır. Bundan dolayı, Vj/Uk oranının artması ile
blok yüzeylerinden gerçekleşen ısı transferinin arttığı gözlemlenmiştir.
Anahtar Kelimeler
Askerî Cihazlar Elektronik Soğutma Çapraz Akış Laminer Akış Isı Transferi Duyulur Isı
Kaynakça
- Kaynakça
- Makaleler
- Chiang, K.T. (2007). Modeling and Optimization of Designing Parameters for a Parallel-Plain Fin Heat Sink with Confined Impinging Jet using The Response Surface Methodology. Applied Thermal Engineering, 27, 2473– 2482. Csernyei, C., Straatman, A.G., (2016). Forced Convective Heat Transfer on a Horizontal Circular Cylinder due to Multiple Impinging Circular Jets. Applied Thermal Engineering, 105, 290–303. Guoneng, L., Zhihua, X., Youqu, Z., Wenwen, G. ve Cong, D. (2016). Experimental Study on Convective Heat Transfer from a Rectangular Flat Plate by Multiple Impinging Jets in Laminar Cross Flows. International Journal of Thermal Sciences, 108, 123-131. Hayee, M.W., Tekasakul, P., Eiamsa-ard, S. ve Nuntadusit, C. (2015). Flow and Heat Transfer Characteristics of in-Line Impinging Jets With Cross-Flow At Short Jet-To-Plate Distance. Experimental Heat Transfer, 28, 511-530. Heo, M.W., Lee, K.D. ve Kim, K.Y. (2011). Optimization of an Inclined Elliptic Impinging Jet with Cross Flow for Enhancing Heat Transfer. Heat Mass Transfer, 47, 731–742. Jeng, T.M., Hsu, W.T. (2016). Experimental Study of Mixed Convection Heat Transfer on the Heated Plate with the Circular-Nozzle Synthetic Jet. International Journal of Heat and Mass Transfer, 97, 559–568. Lafouraki, B.Y., Ramiar, A., Ranjbar, A.A. (2014). Laminar Forced Convection of a Confined Slot Impinging Jet in a Converging Channel. International Journal of Thermal Sciences, 77, 130-138. Maghrabie, H.M., Attalla, M., Fawaz, H.E, ve Khalil, M. (2017). Numerical Investigation of Heat Transfer and Pressure Drop of In-Line Array of Heated Obstacles Cooled by Jet İmpingement in Cross-Flow. Alexandria Engineering Journal, 56, 285-296. Meinders, E.R., Van Der Meer, T.H. ve Hanjalic, K. (1998). Local Convective Heat transfer from an Array of Wall-Mounted Cubes. International Journal of Heat and Mass Transfer, 335-346. Ostheimer, D. ve Yang, Z. (2012). A CFD Study of Twin Impinging Jets in a Cross-Flow. The Open Numerical Methods Journal, 4, 24-34. Popovac, M. ve Hanjalic, K. (2007). Large-Eddy Simulations of Flow over a Jet- Impinged Wall-Mounted Cube in a Cross Stream. International Journal of Heat and Fluid Flow, 28, 1360–1378. Popovac, M. ve Hanjalic, K. (2009). Vortices and Heat Flux around a Wall- Mounted Cube Cooled Simultaneously by a Jet and a Crossflow. International Journal of Heat and Mass Transfer, 52, 4047–4062. Singh, M.K., Yadav, D., Arpit, S., Mitra, S., Saha, S.K. (2016). Effect of nanofluid concentration and composition on laminar jet impinged cooling of heated steel plate. Applied Thermal Engineering, 100, 237–246. Qi, M., Chen, Z. ve Fu, R. (2001). Flow Structure of the Plane Turbulent Impinging Jet in Cross Flow. Journal of Hydraulic Research, 39(2), 155- 161. Rundstrom, D. ve Moshfegh, B. (2006). Investigation of Flow and Heat Transfer of an Impinging Jet in a Cross-Flow for Cooling of a Heated Cube. Journal of Electronic Packaging, 2, 150-157. Shapiro, S., King, J., Karagozian, A. ve M'Closkey, R. (2003). Optimization of Controlled Jets in Crossflow. 41st AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada. Yakhot, A., Liu, H. ve Nikitin, N. (2006). Turbulent Fow around a Wall-Mounted Cube: A Direct Numerical Simulation. International Journal of Heat and Fluid Flow, 27, 994–1009.
- Kitaplar
- Malalasekera, W. ve Versteeg, H.K. (2005). An Introduction to Computational Fluid Dynamics, The Finite Volume Method, Longman.
Öz
Today, rapid development in technology also
accelerates development in all sectors. Military field is also adopting and
applying these technological developments. In addition to these technological
developments, increased competition in military field between countries causes
system developed for military purposes to advance and become more complex.
Various military systems and weapons contain electronic equipment. This
equipment can reach high temperatures during operation. In this case, if this
equipment is not cooled to a secure operating temperature, electronic circuit
elements in this equipment may burn, and this situation disables operation in
all military system. In case of an emergency, to disable military system, these
heated circuit elements should be cooled in a fast and effective way and also
these elements should be kept in safe operating temperatures. Therefore, in
this study, effective cooling for electronic circuit elements inside a military
system is analysed. A block shaped object that represents circuit elements
inserted inside a channel volume that represents the volume of the motherboard
of a military system is considered. It is assumed that this block with high
temperatures is effectively cooled with cross-flow and jet flow together. For this
purpose, air input to channel input is supplied with constant velocity and
cross-flow conditions are met. By providing air input with constant velocity
from a hole on the upper surface of the channel, impinging jet flow conditions
met. Analysis are conducted for calculated Reynolds number 500, 1000, 1500, and
2000 values based on cross-flow air input conditions in laminar way. For these
Reynolds numbers, ratio of jet input air velocity to cross-flow air velocity (Vj/Uk)
rechanged and simulations are repeated for each value. As a result, it is
determined that with increased Reynolds number and Vj/Uk
value, heat transfer on block surface increased as well.
Anahtar Kelimeler
Military Devices Electronic Cooling Cross-Low Laminar Flow Heat Transfer Sensible Heat
Kaynakça
- Kaynakça
- Makaleler
- Chiang, K.T. (2007). Modeling and Optimization of Designing Parameters for a Parallel-Plain Fin Heat Sink with Confined Impinging Jet using The Response Surface Methodology. Applied Thermal Engineering, 27, 2473– 2482. Csernyei, C., Straatman, A.G., (2016). Forced Convective Heat Transfer on a Horizontal Circular Cylinder due to Multiple Impinging Circular Jets. Applied Thermal Engineering, 105, 290–303. Guoneng, L., Zhihua, X., Youqu, Z., Wenwen, G. ve Cong, D. (2016). Experimental Study on Convective Heat Transfer from a Rectangular Flat Plate by Multiple Impinging Jets in Laminar Cross Flows. International Journal of Thermal Sciences, 108, 123-131. Hayee, M.W., Tekasakul, P., Eiamsa-ard, S. ve Nuntadusit, C. (2015). Flow and Heat Transfer Characteristics of in-Line Impinging Jets With Cross-Flow At Short Jet-To-Plate Distance. Experimental Heat Transfer, 28, 511-530. Heo, M.W., Lee, K.D. ve Kim, K.Y. (2011). Optimization of an Inclined Elliptic Impinging Jet with Cross Flow for Enhancing Heat Transfer. Heat Mass Transfer, 47, 731–742. Jeng, T.M., Hsu, W.T. (2016). Experimental Study of Mixed Convection Heat Transfer on the Heated Plate with the Circular-Nozzle Synthetic Jet. International Journal of Heat and Mass Transfer, 97, 559–568. Lafouraki, B.Y., Ramiar, A., Ranjbar, A.A. (2014). Laminar Forced Convection of a Confined Slot Impinging Jet in a Converging Channel. International Journal of Thermal Sciences, 77, 130-138. Maghrabie, H.M., Attalla, M., Fawaz, H.E, ve Khalil, M. (2017). Numerical Investigation of Heat Transfer and Pressure Drop of In-Line Array of Heated Obstacles Cooled by Jet İmpingement in Cross-Flow. Alexandria Engineering Journal, 56, 285-296. Meinders, E.R., Van Der Meer, T.H. ve Hanjalic, K. (1998). Local Convective Heat transfer from an Array of Wall-Mounted Cubes. International Journal of Heat and Mass Transfer, 335-346. Ostheimer, D. ve Yang, Z. (2012). A CFD Study of Twin Impinging Jets in a Cross-Flow. The Open Numerical Methods Journal, 4, 24-34. Popovac, M. ve Hanjalic, K. (2007). Large-Eddy Simulations of Flow over a Jet- Impinged Wall-Mounted Cube in a Cross Stream. International Journal of Heat and Fluid Flow, 28, 1360–1378. Popovac, M. ve Hanjalic, K. (2009). Vortices and Heat Flux around a Wall- Mounted Cube Cooled Simultaneously by a Jet and a Crossflow. International Journal of Heat and Mass Transfer, 52, 4047–4062. Singh, M.K., Yadav, D., Arpit, S., Mitra, S., Saha, S.K. (2016). Effect of nanofluid concentration and composition on laminar jet impinged cooling of heated steel plate. Applied Thermal Engineering, 100, 237–246. Qi, M., Chen, Z. ve Fu, R. (2001). Flow Structure of the Plane Turbulent Impinging Jet in Cross Flow. Journal of Hydraulic Research, 39(2), 155- 161. Rundstrom, D. ve Moshfegh, B. (2006). Investigation of Flow and Heat Transfer of an Impinging Jet in a Cross-Flow for Cooling of a Heated Cube. Journal of Electronic Packaging, 2, 150-157. Shapiro, S., King, J., Karagozian, A. ve M'Closkey, R. (2003). Optimization of Controlled Jets in Crossflow. 41st AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada. Yakhot, A., Liu, H. ve Nikitin, N. (2006). Turbulent Fow around a Wall-Mounted Cube: A Direct Numerical Simulation. International Journal of Heat and Fluid Flow, 27, 994–1009.
- Kitaplar
- Malalasekera, W. ve Versteeg, H.K. (2005). An Introduction to Computational Fluid Dynamics, The Finite Volume Method, Longman.
Ayrıntılar
| Birincil Dil | Türkçe |
|---|---|
| Konular | Mühendislik |
| Bölüm | Makaleler |
| Yazarlar | |
| Yayımlanma Tarihi | 7 Mayıs 2019 |
| Gönderilme Tarihi | 13 Ağustos 2018 |
| Yayımlandığı Sayı | Yıl 2019 |
Cited By
Türbülanslı akışta yüzeyle aynı hizada monte edilmiş elektronik yongalardan olan ısı transferi üzerine geri basamak etkisinin hesaplamalı olarak araştırılması
Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi
https://doi.org/10.17341/gazimmfd.1171341