SIVI NİTROJEN İLE SUNİ DOLU YAPIMI VE ŞİMDİYE KADAR YAPILAN YAPAY DOLULARLA KARŞILAŞTIRILMASI

Yıl 2020, , 1180 - 1189, 25.12.2020

Gokalp Yilmaz , Mehmet Eren Uz , Mohammad Dawood , Dilara Kop

https://doi.org/10.21923/jesd.672264

Cited By: 1

Öz

Dolu, tanım olarak, donmuş katı bir şekilde yeryüzüne düşen su parçacıklarıdır. Boyutları 20 cm’ye kadar çıkabilmektedir. Bu sert kütleler yeryüzüne 80 ile 110 km/s lik hızlarla çarpmakta, ancak bu çarpışmaya rağmen kırılmamaktadırlar. Doluların bu kütle ve hızlarda verdikleri zarar ise bir hayli fazladır. Örneğin; İspanya’nın Alicante şehrinde 2019’un Ağustos ayında gerçekleşen dolu fırtınası 3 milyon euro değerinde zarar vermiştir. Araba kaportalarına, uçak gövdelerine, evlerin çatılarına, solar panellere, rüzgâr türbinlerine verdikleri zarar her yıl milyonlarca lira kayba neden olmaktadır. Tüm bunlara rağmen dolu ile ilgili çalışmalar, dolunun simüle edilememesi ve dolayısıyla dolunun verdiği hasarın da tam olarak simüle edilememesinden dolayı tam başarıya ulaştığı söylenememektedir. Bu çalışmada daha önceden yapılmamış ve literatüre geçmemiş olan sıvı nitrojen ve su ile suni dolu yapılmaktadır. Daha önceden dolu hasar testlerinde kullanılan çelik toplar, indentörler, normal buz küreleri gibi uygulamaların gerçeğe yakın sonuçlar vermediği ve dolu karakteristiği gösteremediği saptanmıştır. Bu eksiklik, yaptığımız “suni dolunun” gerçekle çok yakın karakterde olduğunun ispatı ile giderilmiştir. İşbu ispat dolunun kırılmaması, atış testlerinde benzer sonuçlar vermesi, suni dolunun yoğunluğu gibi parametrelerin gerçek doluya yakın olması sonucunda pekiştirilmiştir.

Anahtar Kelimeler

Dolu, Sıvı nitrojen, Yapay dolu, Dolu Darbe Testi

PRODUCTION OF ARTIFICIAL HAILSTONE WITH LIQUID NITROGEN AND COMPARISONS WITH OTHER ARTIFICIAL HAILSTONES UP TO NOW

Öz

Hailstones are, by definition, particles of water that fall into the Earth in a frozen solid. Its dimensions can be up to 20 cm. These hard masses strike the Earth at speeds of 80 to 110 km/h, but they do not break despite this collision. The damage caused by hail at this mass and speed is a great deal. For example, a hailstorm in August 2019 in Alicante, Spain, caused 3 million euros worth of damage. The damage they do to car bodywork, aircraft bodies, roofs of houses, solar panels, and wind turbines causes millions of Turkish liras of losses each year. In spite of all this, the studies related to hail cannot be said to have achieved full success due to the inability to simulate hailstones and therefore the damage caused by hailstones can not be fully simulated.
In this study, artificial hailstones are made with liquid nitrogen and water, which have not been done before and have not been passed to the literature. It was determined that applications such as steel balls, indentors, normal ice spheres used in hail damage tests did not produce real results and did not show hail characteristics. This deficiency has been eliminated by the proof that the “artificial hailstones” we have made is very close to reality. This proof is confirmed as a result of not breaking the hailstones, giving similar results in firing tests, and parameters such as the density of the artificial hailstones being close to the actual hailstones.

Anahtar Kelimeler

Hailstone, Liquid nitrogen, Artificial hailstone, Hailstone Impact Test

Kaynakça

• Sain, T. and Narasimhan, R., (2011), Constitutive Modeling of Ice in The High Strain Rate Regime. International Journal of Solids and Structures, 48, 817-827.
• Knight, C.A. and Knight, N.C., (1976), Hail Embryo Studies. International Conference on Cloud Physics, Boulder, Colorado. Boston, Mass. American Meteorological Society. United States.
• Crenshaw, B.V. and Koontz, J.D., (2002), Hail : Sizing It Up !Western Roofing Magazine, 2–7.
• https://www.iii.org/fact-statistic/facts-statistics-hail#top
• Uz ME, Yilmaz G, Bircan T (2017) The making of a hailstone simulated realistic damage. Journal of Engineering Sciences and Design 5(2):411–423. https://doi.org/10.21923/jesd.327312.
• Uz ME, Teh L, Maguire J (2014) Developing Australia’s first hailproof roofing profiles. Research case study. Open Days’s poster, SBRC
• Shi, M. F.; Brindza, J.; Michel, P.; Bucklin, P.; Belanger, P. and Prencipe, J., (1997), Static and Dynamic Dent Resistance Performance of Automotive Steel Body Panels. SAE Technical Paper.
• Swift JM (2013) Simulated hail ice mechanical properties and failure mechanism at quasi-static strain rates. University of Washington, USA
• Laurie JAP (1960) Hail and Its Effects on Buildings. vol 176. Research Report, NBRI, Pretoria, South Africa
• Mcccormick, M.; Fekete, J.; Meuleman, D. and Shi, M., (1998), Effect of Steel Strengthening Mechanisms on Dent Resistance of Automotive Body Panels. SAE Technical Paper.11. Nelson S. P., (1983), The influence of storm flow structure on hail growth. J. Atmos. Sci.,40, 1965-1983.
• Nomura, S.; Yutori, Y.; Iwaya, J.; Miyahara, M. and Kokubo, I.A., (1984), Study of the Dynamic Dent Resistance. 13th. Biennial Congress International Deep Drawing Research Group-Efficiency in Sheet Mental Forming.
• Johnson, T.E. and Schaffnit, W.O., (1973), Dent Resistance of Cold-Rolled Low-Carbon Steel Sheet. SAE Technical Paper, 730528
• Fleming, H.G.; Skarajew, M.; Szalla, (1997), J.A.G. A Laboratoy Dent Test for Outer Panel Steels.
• Brimelow, J.C.; Reuter, G.W. and Poolman, E.P. (2002a): Modeling maximum hail size in Alberta thunderstorms. Wea. Forecasting, 17, 1048-1062.
• Dunlop, S., (2008), Oxford Dictionary ofWeather 2nd Ed., New York: Oxford University Press
• Flüeler, P.; Stucki, M.; Guastala, F. and Egli, T., (2008), Hail Impact Resistance of Building Materials Testing, Evaluation and Classification. 11DBMC International Conference on Durability of Building Materials and Components ISTANBUL. Turkey: Istanbul Technical University, Istanbul, Turkey.
• https://agroinsurance.com/en/spain-hail-storms-in-province-of-alicante-cause-3-million-euro-worth-of-damage/