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Journals / Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi / 2025 / Cilt: 40 Sayı: 4

Numerical modelling of the aerodynamic effect of the distance between two vehicles following each other

Birbirini takip eden iki aracın aralarında bulunan mesafenin aerodinamik etkisinin sayısal modellemesi

İbrahim Taş(PAMUKKALE ÜNİVERSİTESİ, TEKNOLOJİ FAKÜLTESİ, OTOMOTİV MÜHENDİSLİĞİ BÖLÜMÜ)0000-0001-5014-4705
Orhan Dedeoğlu(Karsan Otomotiv Sanayii ve Tic. A.Ş.)0000-0001-7791-6509
Pages
2613–2626
Publication Date
2025-12-31
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AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

The outcomes of this study provide a physically coherent foundation for future aerodynamic design and optimization efforts targeting platooning and convoy scenarios.

📌 3 Key Takeaways

🎯
Objective & Hypothesis:This study presents a systematic investigation of aerodynamic interactions between road vehicles traveling in convoys, utilizing the Ahmed Body as a reference geometry.
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Key Findings & Data:Numerical simulations were conducted using Computational Fluid Dynamics (CFD) to examine the leader-trailing vehicle configuration at various inter-vehicle distances (0.125 L, 0.25 L, 0.50 L, 1.0 L, and 2.0 L).
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Conclusion & Impact:The outcomes of this study provide a physically coherent foundation for future aerodynamic design and optimization efforts targeting platooning and convoy scenarios.
🔬Design:Modeling & Simulation
📍Scope:Comprehensive Sample
⚙️Variables:Konvoy aerodinamiği · hesaplamalı akışkanlar dinamiği · iz etkileşimi

Abstract

This study presents a systematic investigation of aerodynamic interactions between road vehicles traveling in convoys, utilizing the Ahmed Body as a reference geometry. Numerical simulations were conducted using Computational Fluid Dynamics (CFD) to examine the leader-trailing vehicle configuration at various inter-vehicle distances (0.125 L, 0.25 L, 0.50 L, 1.0 L, and 2.0 L). Initially, a mesh independence study was performed for the isolated Ahmed Body model, and the resulting drag coefficient (Cd) showed strong agreement with experimentally reported values in the literature. Following this validation, the aerodynamic influence of wake structures in a convoy scenario was analyzed in detail. The simulation results revealed that the trailing vehicle consistently exhibited higher drag coefficients compared to the leader vehicle, primarily due to turbulent wake structures impinging on its frontal area. In contrast, the drag coefficient of the leader vehicle was observed to decrease significantly at reduced inter-vehicle distances, attributed to the back-pressure effects generated by the follower vehicle within the wake region. Surface pressure (Cp) and velocity distributions demonstrated that, particularly at 0.25 L spacing, the wake induced a positive pressure zone behind the leader and a negative pressure zone ahead of the follower. Comparative evaluations based on normalized Cd/Cd,isolated and Cp/Cp,isolated ratios indicated consistent trends with existing literature findings. The outcomes of this study provide a physically coherent foundation for future aerodynamic design and optimization efforts targeting platooning and convoy scenarios.

Özet

Bu çalışma, konvoy hâlinde seyreden kara taşıtları arasındaki aerodinamik etkileşimleri, Ahmed Body referans geometrisi üzerinden sistematik olarak analiz etmiştir. Hesaplamalı Akışkanlar Dinamiği (HAD) yöntemi kullanılarak yürütülen sayısal simülasyon çalışmalarında, lider ve takip araç konfigürasyonları farklı takip mesafeleri (0,125 L, 0,25 L, 0,50 L, 1,0 L, 2,0 L) için incelenmiştir. Başlangıçta tekil Ahmed Body modeli için ağdan bağımsızlık çalışması ile elde edilen sürüklenme katsayısı (Cd) literatürde bildirilen deneysel sonuçlarla uyum göstermiştir. Doğrulama sonrasında, konvoy araç senaryosunda iz yapısının aerodinamik etkileri ayrıntılı biçimde değerlendirilmiştir. Analiz sonuçları, takip aracının her durumda lider araca kıyasla daha yüksek Cd değerleri sergilediğini ve iz bölgesinden kaynaklanan türbülanslı yapıların bu sonucu doğrudan etkilediğini göstermektedir. Lider araç Cd katsayısında ise takip mesafesi azaldıkça belirgin bir azalma gözlenmiş, bu durum iz bölgesindeki geri besleme basıncı ile ilişkilendirilmiştir. Yüzey basınç (Cp) ve hız dağılımı analizleri, özellikle 0,25 L mesafesinde lider araç arkasında pozitif, takip araç önünde negatif basınç etkileri yarattığını ortaya koymuştur. Normalize edilmiş Cd/Cd,izole ve Cp/Cp,izole oranları üzerinden yapılan karşılaştırmalı değerlendirmelerde, mevcut literatürle benzer eğilimler gözlenmiştir. Elde edilen bulgular, konvoy aerodinamiğine yönelik tasarım ve optimizasyon çalışmalarına fiziksel olarak tutarlı bir temel sunmaktadır.

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Cite This Article

Taş, İ., Dedeoğlu, O. (2025). Numerical modelling of the aerodynamic effect of the distance between two vehicles following each other. Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi, Cilt: 40 Sayı: 4, 2613–2626. https://doi.org/10.17341/gazimmfd.1561876

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