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Purpose: This paper aims to investigate the effect of different wing height layouts on the aerodynamic performance and flow structure of high-speed train, in a train-wing coupling method with multiple tandem wings installed on the train roof. Design/methodology/approach: The improved delayed detached eddy simulation method based on shear stress transport k- ω turbulence model has been used to conduct computational fluid dynamics simulation on the train with three different wing height layouts, at a Reynolds number of 2.8 × 106. The accuracy of the numerical method has been validated by wind tunnel experiments. Findings: The wing height layout has a significant effect on the lift, while its influence on the drag is weak. There are three distinctive vortex structures in the flow field: wingtip vortex, train body vortex and pillar vortex, which are influenced by the variation in wing height layout. The incremental wing layout reduces the mixing and merging between vortexes in the flow field, weakening the vorticity and turbulence intensity. This enhances the pressure difference between the upper and lower surfaces of both the train and wings, thereby increasing the overall lift. Simultaneously, it reduces the slipstream velocity at platform and trackside heights. Originality/value: This paper contributes to understanding the aerodynamic characteristics and flow structure of a high-speed train coupled with wings. It provides a reference for the design aiming to achieve equivalent weight reduction through aerodynamic lift synergy in trains. [ABSTRACT FROM AUTHOR]

Byline: Vince Bond Jr. The wind tunnel at Stellantis' North America research and technical center is where product developers and the creative dreams of designers converge to blend visual aesthetics [...]

Regulars / TOP GEAR The Latest Gear Cycling is constantly evolving & here we look at some of the latest gear spotted by Nat Bromhead. Factor Hanzo Track Bike After [...]

Byline: robertsailo Stellantis has unveiled a significant $29.5m investment in Moving Ground Plane (MGP) technology at its research and technical centre in Auburn Hills, Michigan. The MGP system features belts [...]

Byline: Autocar Pro News Desk Taiwanese technology giant Hon Hai Technology Group (Foxconn) has taken the covers off two all-new electric vehicles at the fifth annual Hon Hai Tech Day [...]

When a customer comes into my store - more often than not - they have a predetermined opinion on what type of bike they need, based on the manufacturers descriptions, [...]

Leadout / Factor Ostro LEAD OUT Making good great It took Factor four years and a new factory, but the Ostro VAM is now a much-improved bike Words Sam Challis [...]

Following recent lab tests in the wind tunnel to discern the difference in aerodynamic drag between key superbikes, wheels, and helmets, the tech team at Cyclingnews has been back in [...]

Byline: Jesse Crosse, Autocar UK German marque's aero team helped sculpt A6 E-tron's exterior for a drag coefficient of 0.21Cd. Aerodynamics is one of those unseen things that most of [...]

Byline: Paul Norman All the different categories of road bikes explained What is a road bike? Well, that's a bit trickier to pin down than you might think. At first [...]

What is a road bike? Well, that’s a bit trickier to pin down than you might think. At first glance, you’d probably picture a bike with skinny tyres and drop [...]

Aero is everything. It’s a mantra that’s been used in road racing for many years, and gravel racing is catching up –if not surpassing the trend– fast. It started with [...]

Byline: Neal Hunt FSA has included an extra loop on its latest gravel handlebar, but does that add comfort or just get in the way on the trail? Full Speed [...]

Aaron Gold A car’s rear diffuser is typically shaped to manage airflow, improve aerodynamics, and—let’s be honest—look bitchin’. The new Tourbillon’s massive piece accomplishes all that, but it also does [...]

NEWS LOST & FOUND COMPILED BY MICHAEL WARE AIRFLOW PAIR REAPPEARS IN SWEDEN The Chrysler Airflow, designed in collaboration with aviator Orville Wright, beautifully demonstrated the first forays into aerodynamics [...]

Words Sam Challis Photography Tapestry ‘The instructions I gave our design team when it came to revising the original Ostro basically amounted to “just don’t screw it up”,’ says Factor [...]

Purpose: This study aims to investigate the morphing concepts able to manipulate the dynamics of the downstream unsteadiness in the separated shear layers and, in the wake, be able to modify the upstream shock–boundary layer interaction (SBLI) around an A320 morphing prototype to control these instabilities, with emphasis to the attenuation or even suppression of the transonic buffet. The modification of the aerodynamic performances according to a large parametric study carried out at Reynolds number of 4.5 × 106, Mach number of 0.78 and various angles of attack in the range of (0, 2.4)° according to two morphing concepts (travelling waves and trailing edge vibration) are discussed, and the final benefits in aerodynamic performance increase are evaluated. Design/methodology/approach: This article examines through high fidelity (Hi-Fi) numerical simulation the effects of the trailing edge (TE) actuation and of travelling waves along a specific area of the suction side starting from practically the most downstream position of the shock wave motion according to the buffet and extending up to nearly the TE. The present paper studies through spectral analysis the coherent structures development in the near wake and the comparison of the aerodynamic forces to the non-actuated case. Thus, the physical mechanisms of the morphing leading to the increase of the lift-to-drag ratio and the drag and noise sources reduction are identified. Findings: This study investigates the influence of shear-layer and near-wake vortices on the SBLI around an A320 aerofoil and attenuation of the related instabilities thanks to novel morphing: travelling waves generated along the suction side and trailing-edge vibration. A drag reduction of 14% and a lift-to-drag increase in the order of 8% are obtained. The morphing has shown a lift increase in the range of (1.8, 2.5)% for angle of attack of 1.8° and 2.4°, where a significant lift increase of 7.7% is obtained for the angle of incidence of 0° with a drag reduction of 3.66% yielding an aerodynamic efficiency of 11.8%. Originality/value: This paper presents results of morphing A320 aerofoil, with a chord of 70cm and subjected to two actuation kinds, original in the state of the art at M = 0.78 and Re = 4.5 million. These Hi-Fi simulations are rather rare; a majority of existing ones concern smaller dimensions. This study showed for the first time a modified buffet mode, displaying periodic high-lift "plateaus" interspersed by shorter lift-decrease intervals. Through trailing-edge vibration, this pattern is modified towards a sinusoidal-like buffet, with a considerable amplitude decrease. Lock-in of buffet frequency to the actuation is obtained, leading to this amplitude reduction and a drastic aerodynamic performance increase. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to study the aerodynamic characteristics of Ahmed body in longitudinal and lateral platoons under crosswind by computational fluid dynamics simulation. It helps to improve the aerodynamic characteristics of vehicles by providing theoretical basis and engineering direction for the development and progress of intelligent transportation. Design/methodology/approach: A two-car platoon model is used to compare with the experiment to prove the accuracy of the simulation method. The simplified Ahmed body model and the Reynolds Averaged N-S equation method are used to study the aerodynamic characteristics of vehicles at different distances under cross-winds. Findings: When the longitudinal distance x/L = 0.25, the drag coefficients of the middle and trailing cars at β = 30° are improved by about 272% and 160% compared with β = 10°. The side force coefficients of the middle and trailing cars are increased by 50% and 62%. When the lateral distance y/W = 0.25, the side force coefficients of left and middle cars at β = 30° are reduced by 38% and 37.5% compared with β = 10°. However, the side force coefficient of the right car are increased by about 84.3%. Originality/value: Most of the researches focus on the overtaking process, and there are few researches on the neat lateral platoon. The innovation of this paper is that in addition to studying the aerodynamic characteristics of longitudinal driving, the aerodynamic characteristics of neat lateral driving are also studied, and crosswind conditions are added. The authors hope to contribute to the development of intelligent transportation. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to describe the use of optimization approaches to increase the range of near-future howitzer ammunition. Design/methodology/approach: The performance of a gliding projectile concept is assessed using an aeroballistic workflow, comprising aerodynamic characterization and flight trajectory computation. First, a single-objective optimization is run with genetic algorithms to find the maximal attainable range for this type of projectile. Then, a multi-objective formulation of the problem is proposed to consider the compromise between range and time of flight. Finally, the aerodynamic model used for the gliding ammunition is evaluated, in comparison with direct computational fluid dynamics (CFD) computations. Findings: Applying single-objective range maximization results in a great improvement of the reachable distance of the projectile, at the expense of the flight duration. Therefore, a multi-objective optimization is implemented in a second time, to search sets of parameters resulting in an optimal compromise between fire range and flight time. The resulting Pareto front can be directly interpreted and has the advantage of being useful for tactical decisions. Research limitations/implications: The main limitation of the work concerns the aerodynamic model of the gliding ammunition, which was initially proposed as an alternative to reduce significantly the computational cost of aerodynamic characterization and enable optimizations. When compared with direct CFD computations, this method appears to induce an overestimation of the range. This suggests future evolution to improve the accuracy of this approach. Originality/value: To the best of the authors' knowledge, this paper presents an original ammunition concept for howitzers, aiming at extending the range of fire by using lifting surfaces and guidance. In addition, optimization techniques are used to improve the range of such projectile configuration. [ABSTRACT FROM AUTHOR]

This document provides an overview of rocket aerodynamics optimization, specifically focusing on model rockets. It explains how different components, such as fins, nose cones, and body tube configurations, can improve a rocket's stability and efficiency. The article discusses the advantages and disadvantages of various fin shapes and different types of nose cones at different speeds. It also highlights the importance of body tube length for stability and performance. The document emphasizes the significance of understanding aerodynamics in model rocketry to optimize rocket performance. It mentions the Apogee Aspire rocket as an example of a commercially available rocket designed for maximum speed and altitude. The use of simulation and design tools like RockSim is also mentioned. Overall, the understanding and optimization of aerodynamics can greatly impact the success of model rocket launches. [Extracted from the article]

This article provides a comprehensive overview of McLaren's road car models from 2012 to 2023. It highlights key models such as the 12C, P1, 650S, 675LT, 570S, 720S, Senna, Speedtail, Elva, and Artura. Each model is described in terms of its unique features, performance capabilities, and design elements. The article also mentions limited edition models like the Sabre and Solus GT. Overall, McLaren's road cars are known for their exceptional performance, cutting-edge technology, and distinctive design. [Extracted from the article]

Purpose: The purpose of this study is to propose a precise and standardized strategy for numerically simulating vehicle aerodynamics. Design/methodology/approach: Error sources in computational fluid dynamics were analyzed. Additionally, controllable experiential and discretization errors, which significantly influence the calculated results, are expounded upon. Considering the airflow mechanism around a vehicle, the computational efficiency and accuracy of each solution strategy were compared and analyzed through numerous computational cases. Finally, the most suitable numerical strategy, including the turbulence model, simplified vehicle model, calculation domain, boundary conditions, grids and discretization scheme, was identified. Two simplified vehicle models were introduced, and relevant wind tunnel tests were performed to validate the selected strategy. Findings: Errors in vehicle computational aerodynamics mainly stem from the unreasonable simplification of the vehicle model, calculation domain, definite solution conditions, grid strategy and discretization schemes. Using the proposed standardized numerical strategy, the simulated steady and transient aerodynamic characteristics agreed well with the experimental results. Originality/value: Building upon the modified Low-Reynolds Number k-e model and Scale Adaptive Simulation model, to the best of the authors' knowledge, a precise and standardized numerical simulation strategy for vehicle aerodynamics is proposed for the first time, which can be integrated into vehicle research and design. [ABSTRACT FROM AUTHOR]

The article focuses on Archimedes' principle, exploring its origins, applications in various fields such as shipbuilding and aerohydrodynamics, and its relevance to buoyancy. Topics include the legendary story of King Hiero II and Archimedes, the practical implications of the principle in ship construction and navigation, and its broader application to airships and aerodynamics.

In a novel approach to sustainability, Lufthansa Group is leveraging biomimicry by introducing sharkskin-inspired technology on its aircraft to reduce carbon emissions effectively. This innovative strategy employs a special AeroSHARK [...]

Byline: Paul Brett The Disruptr CFR and Stingr CFR promise improved aerodynamics and feature HighBar's rotary-dial operated chin strap Canyon has launched two brand new cycling helmets that use a [...]

reviewed by Matthew Pioro I had heard that the engineering team at Trek was actually terrified. Back in September 2021, a little more than a year after the third-generation Émonda [...]

The Specialized S-Works Evade III is a range-topping aero road helmet, launched in 2022, used by a handful of professional teams including Soudal QuickStep and SD Worx. It is a […]

Byline: David Kaminski-Morrow French investigators have disclosed that a De Havilland DHC-6 Twin Otter crew resorted to aerodynamic manoeuvring and ground effect to land the aircraft after its engines failed [...]

Increasingly, the cycling industry is realising the necessity of developing system-wide approaches to aerodynamics instead of looking at individual parts and cobbling them together without a thorough understanding of how [...]

Byline: Tony Harrington As climate imperatives increasingly challenge air transport, the sector is desperately seeking new technologies to mitigate damage caused by old ones. As climate imperatives increasingly challenge air [...]

Byline: Josh Croxton Decathlon-AG2R La Mondiale bikes seen using new rubber with unusual tread at Teams Presentation An all-new tyre has been spotted at the Tour de France, using some [...]

An all-new tyre has been spotted at the (https://www.cyclingnews.com/tour-de-france/) Tour de France, using some unusual tread pattern and with an apparent aero benefit. Spotted on the Van Rysel bikes of [...]

It’s hard to conjure a bike more iconic to pro cycling than the Trek Madone. The Madone was born out of the glory years of Lance Armstrong’s now-shamed successive Tour [...]

Fara is an Old Norse word which means ‘to journey’ or ‘to venture’. It is still used in the English words ‘Wayfaring’ and ‘Seafaring’ with the same sense of meaning. [...]

Today, Pinarello has launched its latest incarnation of the Pinarello Dogma F race bike, alongside claims of improved aerodynamics and tangible weight loss - just 6.63kg for the lightest full [...]

TPI Composites, Inc., (TPI) reported its contributions on the Kenworth SuperTruck 2 that is being exhibited at the Advanced Clean Transportation (ACT) Expo in Las Vegas. TPI said the all-composite [...]

KITLIST / Gear Insight ‘TAKE MORE TIME TO CHOOSE A HARNESS THAN A WING’ Advice from the experts on how to prioritise safety when choosing a harness “Pilots are choosing [...]

Features / MK1 FIESTA SMOOTH OPERATOR Built with lessons learned from sportsbikes, this Mk1 Fiesta travels through the air like a Teflon butterfly. Words Daniel Bevis Photos Adrian Brannan Eddies [...]

SPECIALIZED: TARMAC: SL8B Building a great bike is hard. Making a great bike better is even more challenging. Yet every three to four years, brands that make race bikes for [...]

• BEM modeling of a 3D rectangular wing subjected to ground effect. • A wide range of ground heights and positive/negative AOAS are tested in comparison with experiments. • BEM produces quite accurate results for both lift and downforce producing cases. • When dealing with extreme ground effect, the fidelity of BEM remarkably decreases. • The pressure field on the suction side determines whether the wing produces positive or downward forces. Present paper aims to assess the performance and limits of boundary element method for the reliable simulation of ground effect phenomena on hydrodynamic lifting surfaces. Benefitting from the ground effect, especially in extreme ground proximity, suggests a promising concept for lifting bodies. On the other hand, the more pronounced the ground effect, the more complicated flow physics it exhibits, making the problem harder to handle numerically. In this study, a potential-based boundary element method (BEM) is applied to the flow past a 3D rectangular wing within a wide range of ground clearances corresponding to out of ground effect (OGE), in ground effect (GE) and extreme ground effect (EGE) conditions. Both positive and negative angles of attack are tested to examine the lift and downforce producing cases. The potential flow around the airfoil is computed using the mixed constant-strength source and constant-strength dipole based panel method. The results show that BEM successfully predicts the lift force variation for a wing working in ground proximity (GE). However, approaching the bounds of extreme ground effect is seen to introduce a progressive decrease of the fidelity of the method. A similar tendency is observed in the downforce generating conditions, which is also an important scenario for ground vehicle aerodynamics. BEM remarkably overestimates the magnitude of the downforce when the ground clearance reaches up to the EGE conditions, still, it produces quite satisfactory results for the rest of the tested configurations. The pressure distributions are also provided to examine the flow field in the aforementioned cases. Overall, the results lead us to conclude that BEM stands as a robust and reliable prediction tool for ground effect on 3D wings but the extreme ground effect condition represents the limit of its accuracy range. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to investigate the optimal average drag coefficient of the Ahmed body for mixed platoon driving under crosswind and no crosswind conditions using the response surface optimization method. This study has extraordinary implications for the planning of future intelligent transportation. Design/methodology/approach: First, the single vehicle and vehicle platoon models are validated. Second, the configuration with the lowest average drag coefficient under the two conditions is obtained by response surface optimization. At the same time, the aerodynamic characteristics of the mixed platoon driving under different conditions are also analyzed. Findings: The configuration with the lowest average drag coefficient under no crosswind conditions is 0.3 L for longitudinal spacing and 0.8 W for lateral spacing, with an average drag coefficient of 0.1931. The configuration with the lowest average drag coefficient under crosswind conditions is 10° for yaw angle, 0.25 L for longitudinal spacing, and 0.8 W for lateral spacing, with an average drag coefficient of 0.2251. Compared to the single vehicle, the average drag coefficients for the two conditions are reduced by 25.1% and 41.3%, respectively. Originality/value: This paper investigates the lowest average drag coefficient for mixed platoon driving under no crosswind and crosswind conditions using a response surface optimization method. The computational fluid dynamics (CFD) results of single vehicle and vehicle platoon are compared and verified with the experimental results to ensure the reliability of this study. The research results provide theoretical reference and guidance for the planning of intelligent transportation. [ABSTRACT FROM AUTHOR]

The McLaren 750S is a lighter and more powerful version of the McLaren 720S, with a power boost to 740bhp and a weight reduction of 30kg. It offers impressive performance numbers, including a 0-62mph time of 2.8 seconds and a top speed of 206mph. The car has made incremental improvements to its chassis, steering, braking system, and aerodynamics, resulting in a light, precise, and adaptable driving experience. The interior has also been updated with new features. The article compares the McLaren 750S Spider to the Ferrari 296 GTB, highlighting the 750S's intuitive driving experience and trustworthiness in mixed or wet conditions. The car's engine, steering, and lightweight construction are praised, although there are some minor drawbacks mentioned. Overall, the McLaren 750S is described as a thrilling and usable car that provides unfettered access to its performance. [Extracted from the article]

This article discusses the recreation of the AMG-powered G-Wagen that won the Paris-Dakar rally in 1983. The rally was known for its challenges and dangers, but Thierry Sabine, the creator of the race, was inspired by desert motorsport. The Mercedes-Benz France team prepared a modified 280GE for the race, with improvements in performance and aerodynamics. The car, driven by Jacky Ickx and Claude Brasseur, ultimately won the car category of the rally. The article also mentions the recreation of the car by an enthusiast, who worked closely with Mercedes-Benz to build an accurate replica. The car was tested in the 2022 Dakar Classic and performed well. The article concludes with a description of the car's performance on a rally stage, highlighting its power and agility. [Extracted from the article]

The article discusses the Ferrari SF90 XX, which is the fastest road car ever made by Ferrari. The author describes their experience driving the car on a wet track and highlights its impressive acceleration and handling. The SF90 XX is a track-focused car that is also road legal, and it features a powerful 4.0-liter V8 engine and three electric motors. The article emphasizes the car's aerodynamics and downforce, as well as its improved braking performance. The SF90 XX is priced at around $1.56 million and only a limited number will be produced. Overall, the article portrays the SF90 XX as an exhilarating and high-performance vehicle. [Extracted from the article]

This article provides a balanced view of integrated routing in bicycles, which involves hiding brake hoses and derailleur wiring inside the bike's frame or fork. The advantages of integrated routing include improved aerodynamics and a cleaner look, but there are downsides such as increased complexity for bike fitting and limited component choices. Maintenance can also be challenging, leading to noise and friction. The article explores the opinions of experts and cyclists, highlighting the aesthetic appeal of integrated bikes for some riders, while others express concerns about maintenance and repair costs. The author emphasizes that integrated bikes are not the only option available, and urges manufacturers to prioritize supporting their integrated systems and ensuring ease of maintenance for riders. [Extracted from the article]

Byline: Autocar Pro News Desk The new Actros, powered by 12.8-litre OM 471 diesel engine, has a longer front end and further aerodynamic measures to achieve fuel savings of up [...]

—GA Bontrager RSL Aero $460 Built with Trek’s OCLV Carbon construction and featuring an aero-optimized shape, the RSL Aero road bar is an ideal combination of light weight, durability and [...]

The aviation industry's continuous quest for aerodynamic efficiency and innovation is epitomized by the Flying Wing and Blended Wing Body (BWB) aircraft designs. These concepts challenge traditional aircraft architecture by [...]

Boeing is testing a new laser-based technique called Filtered Rayleigh Scattering for Thrust (FRST) to measure jet thrust, replacing current mathematical models. This optical method uses lasers, cameras, and spectroscopy to measure important parameters of gas turbine engines. The technology offers advantages over traditional sensors and probes, supporting the development of more efficient engine core technologies and potentially allowing the measurement of non-carbon dioxide particulate emissions during flight. The test is a collaboration between Virginia Tech University, Pratt & Whitney, and Boeing, and is being demonstrated on a Boeing 747SP flying testbed. Omega Optical, a company specializing in optics, collaborated with another company on a space exploration project, designing and producing filters. They worked closely with the client to understand their objectives and challenges, overcoming obstacles through collaboration. The customer was impressed with Omega Optical's work. [Extracted from the article]