EXPLORING THE IMPACT OF GEOMETRIC PARAMETERS ON HEAT TRANSFER AND FLUID FLOW CHARACTERISTICS IN CROSS-TRIANGULAR GROOVED CHANNELS: A COMPUTATIONAL STUDY

Year 2024, Volume: 44 Issue: 1, 227 - 243, 03.06.2024

Yeliz Alnak

https://doi.org/10.47480/isibted.1494499

Abstract

In this study, the impact of geometric parameters of rectangular baffles with varying location angles and heights is investigated on the heat transfer and fluid flow characteristics of cross-triangular grooved channels. Computational methods are employed to explore these effects, utilizing the Ansys-Fluent program to solve the Navier-Stokes and energy equations, incorporating the k-ε turbulence model for numerical simulations. The inlet temperature of the air, serving as the working fluid, is set at 293 K, while the wall surface temperature of the lower triangular grooved channel remains fixed at 373 K. Rectangular baffles are tested with angles of 30°, 60°, and 90°, and heights of 0.25H, 0.5H, and 0.75H, respectively. The numerical results show good agreement with a 3.53% deviation compared to existing empirical data in the literature. The obtained findings are presented in terms of mean Nusselt (Num) number, fluid temperature, and Performance Evaluation Criterion (PEC) number variations taking into consideration of pressure drop for each rectangular baffle angle and height. Additionally, contour distributions of temperature and velocity are evaluated for different Reynolds numbers (Re) and arrangements of rectangular baffles. It has been determined that the Nu number value increases by 197.56% at a 90° angle and 0.75H height, compared to the 0.25H baffle height at Re=6000. Furthermore, at Re=1000, the PEC number is 84.50% higher with a baffle height of 0.25H and a baffle angle of 30° compared to the condition with a 90° angle.

Keywords

Cross-triangular grooved channels, Rectangular baffles, Heat transfer, Computational fluid dynamics, Navier-Stokes equations

ÇAPRAZ ÜÇGEN YİVLİ KANALLARDA GEOMETRİK PARAMETRELERİN ISI TRANSFERİ VE AKIŞKAN AKIŞ ÖZELLİKLERİ ÜZERİNDEKİ ETKİSİNİN ARAŞTIRILMASI: HESAPLAMALI BİR ÇALIŞMA

Abstract

Bu çalışmada, konum açıları ve yükseklikleri değişen dikdörtgen engellerin geometrik parametrelerinin çapraz üçgen oluklu kanalların ısı transferi ve akışkan akışı özellikleri üzerindeki etkisi araştırılmaktadır. Bu etkileri keşfetmek için hesaplamalı yöntemler kullanılmış olup; Ansys-Fluent programı kullanılarak Navier-Stokes ve enerji denklemleri çözülmüş, sayısal simülasyonlar için k-ε türbülans modeli dahil edilmiştir. Çalışma akışkanı olarak kullanılan havanın giriş sıcaklığı 293 K iken, üçgen oluklu alt kanalın duvar yüzey sıcaklığı sabit 373 K olarak belirlenmiştir. Dikdörtgen engeller sırasıyla 30°, 60° ve 90° açılarında ve 0,25H, 0,5H ve 0.75H yüksekliklerinde test edilmiştir. Sayısal sonuçlar, literatürde mevcut olan deneysel verilere göre %3,53 sapma ile iyi bir uyum göstermektedir. Elde edilen bulgular, her bir dikdörtgen engel açısı ve yüksekliği için ortalama Nusselt (Num) sayısı, akışkan sıcaklığı ve basınç düşüşünü dikkate alan Performans Değerlendirme Kriteri (PEC) sayısı değişimleri açısından sunulmaktadır. Ayrıca, farklı Reynolds sayıları (Re) ve dikdörtgen engellerin düzenlemeleri için sıcaklık ve hız konturu dağılımları değerlendirilmektedir. Re=6000'de 0,25H engel yüksekliğine göre Nu sayısı değerinin 90° açı ve 0,75H yükseklikte %197,56 arttığı belirlenmiştir. Ayrıca, Re=1000'de, 0,25H engel yüksekliği ve 30° açısında, 90° açıdaki durumla karşılaştırıldığında PEC sayısı %84,50 daha yüksektir.

Keywords

Çapraz üçgen oluklu kanallar, Dikdörtgen engeller, Isı transferi, Hesaplamalı akışkanlar dinamiği, Navier-Stokes denklemleri

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