Boundary impingement and attachment of horizontal offset dense jets

Shao, Dongdong; Law, Adrian Wing‐Keung

doi:10.1016/j.jher.2010.11.003

Cited by 19 publications

(10 citation statements)

References 20 publications

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“…Cold water jet bodies formed a density current after the impingement point. Due to cold water jets behave as density jets, their behaviors of jet centerline axis before and after impingement points have been found similar to Nemlioglu [29], Bayat et al [18], Nemlioglu and Sezgin [12] (for ΔT 0 = −5˚C and using duckbill valve) and Nemlioglu and Sezgin [2] (for ΔT 0 = −5˚C and using circular valve) cold water jets studies and Shao and Law [30] brine discharge studies.…”

Section: N Sezgin / Desalination and Water Treatmentsupporting

confidence: 56%

Investigation of horizontal cold water discharge initial dilutions at various temperature differences using duckbill valve

Sezgin

2016

Desalination and Water Treatment

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A B S T R A C TThermal pollution, that is a temperature change in natural water body, can have adverse effects on the organisms in the aquatic environment as river, lake, or ocean. A common cause of thermal pollution is the use of water as a cooling and heating system by power plants, liquefied natural gas (LNG) regasification terminals, and industrial manufacturers. Cold water discharges into a receiving water body, which are mainly originated from LNG regasification terminals from open cycle heating units, are a kind of thermal effluent. Disposal of cold water with an environmentally protective way can be applied as a dilution method using marine outfall systems. In order to obtain a better dilution in a marine outfall, there is a multiport diffuser at the end of the pipeline. Experimentally performed single port analysis of an outfall is a method of initial dilution investigation for performance determination of designed system. Because of the fact that cold water discharge is denser than receiving ambient water in the marine environment, it is a negatively buoyant dense jet. In this study, horizontally discharged cold water jet initial dilutions at various temperatures were experimentally investigated in a laboratory model using duckbill valve discharge port. Three discharge temperature differences were used as ΔT 0 = −3, −5, and −7˚C in the laboratory model for determination of the initial dilutions, S, in the cold water jet centerline. Densimetric Froude numbers (F) were calculated as 446.03, 358.43, and 321.76 for the selected temperature differences, respectively. This laboratory model study was also aimed at obtaining some experimental coefficients, such as impingement point distance, as design criteria for horizontally discharged cold water outfalls using duckbill valves.

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Section: N Sezgin / Desalination and Water Treatmentsupporting

confidence: 56%

Investigation of horizontal cold water discharge initial dilutions at various temperature differences using duckbill valve

Sezgin

2016

Desalination and Water Treatment

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“…Şekil 6'daki verilere göre soğuk-yoğun atıksu jetlerinin merkez eksenlerinde meydana gelen maksimum sıcaklık farklarının nozülden yatay uzaklığa bağlı olarak üç sıcaklık için de hızla azaldığı belirlenmiştir. [34] çalışmalarındaki y/dF~S/F dağılımları ile uyumlu olduğu görülürken, Shao ve Law [33] çalışmasında belirtilen değerlerle kayda değer bir uyum tespit edilememiştir. Ayrıca deneysel sonuçlar, Cederwall [36] modellerinin y/dF~0.5 geçiş bölgesi civarında uyum gösterirken Fischer [35] çalışmasında verilen y/dF >10 aralığının altında kaldığı için bu modelle uyumu belirlenememiştir.…”

Section: Soğuk-yoğun Atıksu Seyrelmeleriunclassified

Determination of some discharge parameters of horizontally discharged cold-dense wastewaters

Sezgin¹

2018

Pamukkale J Eng Sci

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Termal kirlilik, okyanus, göl veya nehir gibi sucul alanlarda ortam sıcaklığının insan faaliyetleri sonucunda artması veya azalması olarak tanımlanır. Termal kirliliğe, enerji santralleri, sıvılaştırılmış doğalgaz terminalleri (LNG) ve endüstriyel tesislerin ısıtma veya soğutma amaçlı kullanılan daha sonra alıcı ortamlara deşarj edilen suları neden olur. Alıcı ortamlara deşarj edilen termal atıksuların en önemli kaynaklarından biri LNG gazlaştırma terminallerinden kaynaklanan soğuk sulardır. Soğuk sular genellikle kıyısal sulara deşarj edilirler. Bu sular deşarj edildikleri alıcı ortamlara göre yoğunluklarının yüksek olması nedeniyle bir çeşit negatif yüzen (batan) jetlerdir. Alıcı ortam canlı türlerine olumsuz etkilerinden dolayı soğuk sular, yüksek seviyede seyrelme sağlayacak şekilde deşarj edilmelidir. Bu çalışmada, yatay olarak deşarj edilen soğuk-yoğun suyun birinci seyrelme ve çarpma noktası gibi bazı deşarj parametreleri laboratuvar ortamında dairesel deşarj portu kullanılarak belirlenmiştir. Soğuk-yoğun atıksuyun alıcı ortam içerisindeki davranışını (jet geometrisini) belirlemek için renk maddesi olarak Rhodamin B ilavesi yapılmıştır. Renklendirilmiş soğukyoğun atıksuyun anlık fotoğraflarını çekmek için yüksek çözünürlüklü kamera ve atıksu jet merkezinde meydana gelen sıcaklık değişimlerini (seyrelmeler) ölçmek için de hassas termal problar kullanılmıştır. Farklı atıksu yoğunlukları elde etmek için-3 °C,-5 °C ve-7 °C gibi üç değişik sıcaklık fark değerleri uygulanmıştır. Bu çalışmada elde edilen sonuçlara göre soğuk su deşarjlarının tabana çökme eğilimde olan negatif yüzen (batan) jet gibi davrandığı belirlenmiştir. Ayrıca bu çalışmada, ortalama normalize edilmiş çarpma noktası mesafesi ve birinci seyrelmenin 2.333 ve 0.491 olduğu bulunmuştur. Thermal pollution is defined as increase or decrease in temperature of an aquatic environment which may be ocean, lake or river by human influence. A common cause of thermal pollution is the use of water as a cooling and heating system by power plants, liquefied natural gas (LNG) re-gasification terminals and industrial manufacturers. One of the important sources of thermal effluents is cold water discharges, which are mainly originated from LNG re-gasification terminals from open cycle heating units. Cold water can be frequently discharged into coastal waters. Due to its high density, cold water discharge is a kind of negatively buoyant jet. Because of some undesired effects of cold water on receiving water species, should be discharged properly into the marine environment with a high level of initial dilution. Some discharge parameters of horizontally discharged cold-dense wastewater such as initial dilutions, impingement points were determined in a laboratory system using circular port in this study. To determine the behavior of the cold-dense wastewater (wastewater jet geometry) Rhodamine B as a colorant was added to the wastewater. A high-resolution camera was used to take snapshots of the colored cold-dense wastewater. Temperature changes (dilutions) in the c...

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“…Wastewater jets that have a lower density than the ambient water often emanate from desalination and municipal activities [1][2][3]. These discharges are known as buoyant jets [4], and improper disposal of these discharges may result in significant environmental and ecological impacts [5,6].…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Numerical Simulations of Buoyant Jets Discharged from a Rosette-Type Multiport Diffuser

Yan

Mohammadian

Chen

2019

JMSE

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In some outfall systems, wastewaters are discharged into ambient water bodies using rosette-type diffusers in the form of multiple buoyant jets, and it is essential to simulate their mixing characteristics for practical applications and optimal design purposes. The mixing processes of a rosette jet group are more complicated than single jets and multiple horizontal or vertical jets, and thus the existing methods cannot be effectively used to simulate their mixing and dilution properties. With the recent advancements in numerical modeling approaches, numerical simulation of wastewater jets as three-dimensional phenomena can be feasible. The present study deals with a fully three-dimensional numerical simulation for buoyant jets discharged from a rosette-type multiport diffuser, with the standard and re-normalization group (RNG) k-ε turbulence models. The simulated results are compared with experimental data, and the results show a good agreement with the experimental data, demonstrating that the numerical model is an efficient and effective tool for simulating rosette jet groups. It was also concluded that the RNG k-ε model leads to better results than the standard k-ε model with a comparable computational cost. The validated model was further utilized to investigate the influences of port inclinations on the mixing behaviors.

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Boundary impingement and attachment of horizontal offset dense jets

Cited by 19 publications

References 20 publications

Investigation of horizontal cold water discharge initial dilutions at various temperature differences using duckbill valve

Investigation of horizontal cold water discharge initial dilutions at various temperature differences using duckbill valve

Determination of some discharge parameters of horizontally discharged cold-dense wastewaters

Three-Dimensional Numerical Simulations of Buoyant Jets Discharged from a Rosette-Type Multiport Diffuser

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