{"title":"利用广义 k-ω (GEKO) 湍流模型研究自由射流和撞击射流","authors":"Ketan Atulkumar Ganatra , Himadri Chattopadhyay , Akanksha Mathur","doi":"10.1016/j.ijheatfluidflow.2024.109660","DOIUrl":null,"url":null,"abstract":"<div><div>The present numerical study focuses on a novel generalized <em>k</em>–ω (GEKO) turbulence model. The model has unique feature of tunable free model parameters C<sub>mix</sub> (mixing) and C<sub>jet</sub> (jet) applicable for free jets along with C<sub>sep</sub> (separation) and C<sub>nw</sub> (near wall) used for impinging jets. The slot and circular free jets and impinging jets are employed to assess the model’s consistency in multiple flow aspects. The impinging surfaces are flat plate and cylinder and air is working fluid. Parameters such as velocity, turbulence intensity, turbulence viscosity ratio and Nusselt number are investigated for free and impinging jets. The free parameters have specific range where C<sub>mix</sub> = 0.15–0.95, C<sub>jet</sub> = 0–1, C<sub>sep</sub> = 0.7–2.5 and C<sub>nw</sub> = − 2 to 2. The numerical results from C<sub>mix</sub> = 0.2 for circular jet, C<sub>mix</sub> = 0.3–0.4 for slot jet; C<sub>jet</sub> = 0.9 and C<sub>nw</sub> = 0.5 for both jet configurations are consistent with existing literature. C<sub>sep</sub> = 1.75 for slot jet whereas C<sub>sep</sub> = 1–2.5 for circular jet are considered as ideal for numerical prediction. The GEKO turbulence model offers additional feature of production limiter which prevents turbulence increment in stagnation region for impinging jets. Therefore in present study over prediction of numerical heat transfer than experimental is limited to 35 % whereas previous studies have reported it as high as 300 %. Moreover, the GEKO turbulence model is compared with high cost Large Eddy Simulation (LES) which shows excellent numerical competency with LES.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"111 ","pages":"Article 109660"},"PeriodicalIF":2.6000,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Investigation of free and impinging jets using generalized k–ω (GEKO) turbulence model\",\"authors\":\"Ketan Atulkumar Ganatra , Himadri Chattopadhyay , Akanksha Mathur\",\"doi\":\"10.1016/j.ijheatfluidflow.2024.109660\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The present numerical study focuses on a novel generalized <em>k</em>–ω (GEKO) turbulence model. The model has unique feature of tunable free model parameters C<sub>mix</sub> (mixing) and C<sub>jet</sub> (jet) applicable for free jets along with C<sub>sep</sub> (separation) and C<sub>nw</sub> (near wall) used for impinging jets. The slot and circular free jets and impinging jets are employed to assess the model’s consistency in multiple flow aspects. The impinging surfaces are flat plate and cylinder and air is working fluid. Parameters such as velocity, turbulence intensity, turbulence viscosity ratio and Nusselt number are investigated for free and impinging jets. The free parameters have specific range where C<sub>mix</sub> = 0.15–0.95, C<sub>jet</sub> = 0–1, C<sub>sep</sub> = 0.7–2.5 and C<sub>nw</sub> = − 2 to 2. The numerical results from C<sub>mix</sub> = 0.2 for circular jet, C<sub>mix</sub> = 0.3–0.4 for slot jet; C<sub>jet</sub> = 0.9 and C<sub>nw</sub> = 0.5 for both jet configurations are consistent with existing literature. C<sub>sep</sub> = 1.75 for slot jet whereas C<sub>sep</sub> = 1–2.5 for circular jet are considered as ideal for numerical prediction. The GEKO turbulence model offers additional feature of production limiter which prevents turbulence increment in stagnation region for impinging jets. Therefore in present study over prediction of numerical heat transfer than experimental is limited to 35 % whereas previous studies have reported it as high as 300 %. Moreover, the GEKO turbulence model is compared with high cost Large Eddy Simulation (LES) which shows excellent numerical competency with LES.</div></div>\",\"PeriodicalId\":335,\"journal\":{\"name\":\"International Journal of Heat and Fluid Flow\",\"volume\":\"111 \",\"pages\":\"Article 109660\"},\"PeriodicalIF\":2.6000,\"publicationDate\":\"2024-11-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Heat and Fluid Flow\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0142727X24003850\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENGINEERING, MECHANICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Heat and Fluid Flow","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0142727X24003850","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
Investigation of free and impinging jets using generalized k–ω (GEKO) turbulence model
The present numerical study focuses on a novel generalized k–ω (GEKO) turbulence model. The model has unique feature of tunable free model parameters Cmix (mixing) and Cjet (jet) applicable for free jets along with Csep (separation) and Cnw (near wall) used for impinging jets. The slot and circular free jets and impinging jets are employed to assess the model’s consistency in multiple flow aspects. The impinging surfaces are flat plate and cylinder and air is working fluid. Parameters such as velocity, turbulence intensity, turbulence viscosity ratio and Nusselt number are investigated for free and impinging jets. The free parameters have specific range where Cmix = 0.15–0.95, Cjet = 0–1, Csep = 0.7–2.5 and Cnw = − 2 to 2. The numerical results from Cmix = 0.2 for circular jet, Cmix = 0.3–0.4 for slot jet; Cjet = 0.9 and Cnw = 0.5 for both jet configurations are consistent with existing literature. Csep = 1.75 for slot jet whereas Csep = 1–2.5 for circular jet are considered as ideal for numerical prediction. The GEKO turbulence model offers additional feature of production limiter which prevents turbulence increment in stagnation region for impinging jets. Therefore in present study over prediction of numerical heat transfer than experimental is limited to 35 % whereas previous studies have reported it as high as 300 %. Moreover, the GEKO turbulence model is compared with high cost Large Eddy Simulation (LES) which shows excellent numerical competency with LES.
期刊介绍:
The International Journal of Heat and Fluid Flow welcomes high-quality original contributions on experimental, computational, and physical aspects of convective heat transfer and fluid dynamics relevant to engineering or the environment, including multiphase and microscale flows.
Papers reporting the application of these disciplines to design and development, with emphasis on new technological fields, are also welcomed. Some of these new fields include microscale electronic and mechanical systems; medical and biological systems; and thermal and flow control in both the internal and external environment.