National Wind Tunnel Facility
Lead Research Organisation:
Loughborough University
Department Name: Aeronautical and Automotive Engineering
Abstract
Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.
Organisations
People |
ORCID iD |
| Gary Page (Principal Investigator) |
| Title | Air Jet Flow Control On Pitching Aerofoil |
| Description | Dynamic stall occurs when a wing or rotor blade exceeds the stall angle, leading to sudden flow separation and the formation of a strong vortex near the leading edge. This results in sharp increases in lift, drag, and pitching moments. It is commonly observed in systems such as helicopter rotors and wind turbines, where rapid motion or oscillations create highly transient flow conditions, impacting performance and contributing to structural fatigue. In helicopters, dynamic stall significantly limits the safe flight envelope, causing low-speed flow separation on retreating rotor blades during high angles of attack. This process generates a strong stall vortex, resulting in momentary high lift, drag forces, and pitching moments that affect both performance and rotor durability. This experimental study explores the use of air jet vortex generators (AJVGs) to control dynamic stall in low-speed conditions. AJVGs are devices designed to control boundary layer separation and delay stall by injecting air into the flow over an aerofoil. Initial studies by Wallis in 1952[1] demonstrated the potential of air jets for turbulent mixing and re-energizing the boundary layer. Subsequent research has identified optimal jet and pitch angles that effectively enhance mixing. Pulsed AJVGs have been found to be more efficient than steady blowing, providing better stall suppression with reduced mass flow requirements[2]. Studies by Seifert et al.[3] and McManus et al.[4] highlighted the importance of parameters such as the jet-to-freestream velocity ratio (VR), pulsing frequency (F+), and duty cycle, which influence the generation of vortical structures and the effectiveness of AJVGs in suppressing boundary layer separation. This work presents experimental datasets using both steady and pulsed AJVGs to suppress dynamic stall on a sinusoidal pitching RAE9645 aerofoil. Tests at a Reynolds number of 1 million and reduced pitching frequencies between 0.01 and 0.10 evaluated the effects of jet momentum coefficient, duty cycle, and pulsing frequency on dynamic stall suppression. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2025 |
| Provided To Others? | Yes |
| Impact | Only just available. |
| URL | https://www.nwtf.ac.uk/dataset/air-jet-flow-control-on-pitching-aerofoil/ |
| Title | Automotive DrivAer model - Fastback, Notchback, Estate back |
| Description | The urgency of reducing carbon dioxide emissions has placed immense pressure on the automotive industry to lower their environmental footprint. One of the remaining areas with significant potential for improvement is vehicle aerodynamics, which can lead to substantial economic benefits through drag reduction. Understanding the flow field around a typical car geometry is crucial to unlocking these savings. Traditional studies often focus on simplified car models like the Ahmed body and the SAE model due to their extensive validation data. These models help isolate basic flow structures by minimizing interference effects, but they fall short in replicating the complex flow phenomena found in real vehicles, such as the flow around wheelhouses and the interaction between the car underbody and the road . Advances in computational and experimental resources now allow for more detailed and realistic investigations without excessive cost. Therefore, here we have investigated the wake flow characterstics of the realistic car model, DrivAer. This model was developed at Technische Universität München, in collaboration with Audi AG and the BMW Group[1,2]. This realistic generic car model has been designed with three different rear geometries, Fastback, Notchback and Estate back. In this work, a 25% scale model of the DrivAer automotive model with all three rear-end geometries was studied, and the model used was on loan from FKFS Stuttgart. One of the primary aims is to provide high-quality validation data, which is achieved through a comprehensive series of measurements, including forces, moments, pressures, and off-body PIV measurements for the three rear-end configurations. All results from these measurements can be found in Varney et al. [3], which offers a detailed description of the test conditions and wind tunnel setup, along with access to the full dataset. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | Only just published. |
| URL | https://www.nwtf.ac.uk/dataset/drivaer-experimental-aerodynamic-dataset/ |
| Title | Axisymmetric Body |
| Description | Bluff body wakes are prevalent in many areas of interest including road vehicles, energy systems and environmental flows. The low pressure in the wake creates a pressure deficit on the base and is a large source of aerodynamic drag. The unsteady pressure fluctuations can also be a significant noise source. By adopting a body of revolution with a streamlined nose, the base flow can be isolated from most upstream effects and so allows a fundamental study of the flow dynamics in the wake. Data is presented for the near-wake of an axisymmetric body using base pressure tappings and large scale Particle Image Velocimetry measurements. The experimental data aims to answer the key questions: at higher Reynolds number does the very low frequency dynamics influence the three-dimensional structure of the near-wake? What are the factors leading to the selection of either an axisymmetric topology or a reflectional symmetry preserving state as low-drag conditions? A detailed analysis of this dataset is presented in Pavia, G. et al (2019)[1]. In this experiment, Tomographic Particle Image Velocimetery (TPIV) and 2D PIV measurements were conducted on the near-wake region of an axisymmetric body. For the complete dataset, the user can download it from the Loughborough University repository. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | Only just available. |
| URL | https://www.nwtf.ac.uk/dataset/axisymmetric/ |
| Title | SAE 20 Degree Notchback Automotive Reference Model |
| Description | The aerodynamic drag of a road vehicle has a major impact on CO2CO_2CO 2 emissions for combustion engine vehicles and range for battery electric vehicles. A significant component of drag is that associated with the large region of separated flow at the rear of the vehicle. Real world cars have complex geometric detail and it is a common practice to study simplified bodies that focus on generic flow features. Cogotti at Pininfarina studied a generic body [1] that was later adapted by the Society of Automotive Engineers (SAE) for studies of model interference in wind tunnels[2]. It has a variety of rear end geometries, and the 'notchback' variant used here is representative of a saloon car with a boot (or trunk). Experimentally these reference models allow a better understanding of the fundamental flow features and how these change with geometric modifications and this data is then especially useful for the validation of computational simulation models. The wind tunnel measurements use a 1/5 scale model and the notchback angle is at 20 degrees (measured from the horizontal). This dataset aims to capture the flow details in the notch and shows a typical notch back flow structure with asymmetry in the trailing vortex structure and in the impingement on the boot-deck. Weak separation on the slant with flow displaced above the boot-deck is highlighted and the correlation between the Particle Image Velocimetry (PIV) results and the surface pressures is demonstrated. Measurements includes force and moment data, surface pressures for the centerline, slant, boot-deck and base and detailed PIV data for the impingement region, model centerline, A-pillar and multiple planes on the slant and boot-deck. Time averaged, statistical and instantaneous data are available. Further information on this dataset is presented in Wood, D. et al (2014)[3]. The full dataset is available from the Loughborough University repository. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | This data has been used as a reference case for the 1st Automotive CFD workshop and has been simulation by around 20 groups across academia and industry throughout the world. It has helped improved the accuracy of automotive CFD prediction. |
| URL | https://www.nwtf.ac.uk/dataset/sae-20-degree-notchback-automotive-reference-model-2/ |
| Title | Two-Bladed Propeller Performance in Inclined Flow |
| Description | Propellers offer a unique advantage in aircraft propulsion at speeds up to Mach 0.8[1], often outperforming other systems. Despite this, civil aviation in the Mach 0.6-0.8 range has historically relied on turbofans. This preference is due to several factors: the technical challenges of managing compressibility effects on propellers, limited emissions regulations in the past, and the long-standing availability of affordable fossil fuels. However, recent shifts in the industry are bringing propellers back into focus. Advances in high-speed propeller blade designs have helped address earlier technical barriers, while growing emphasis on reducing emissions and improving fuel efficiency has made propellers increasingly attractive. Research on propeller behavior, however, has remained somewhat fragmented. A key gap exists in understanding how propellers perform when exposed to inclined airflow, an essential aspect for accurate aerodynamic modeling. Most of the experimental data on this topic is outdated, derived from studies conducted mainly in the first half of the 20th century. Early research focused on basic aerodynamic forces and stability effects but lacked the precision and detail needed for comprehensive modeling[2][3][4]. Later studies explored specific phenomena like force oscillations and wake composition using strain gauges and pressure rakes but still offered limited insights due to low temporal and spatial resolution. This work aims to address these gaps by focusing on propeller inflow, which includes both induced and incident flow components. Induced flow refers to the airflow changes caused by the propeller's thrust generation, while incident flow represents the natural airflow environment around the propeller. Accurate modeling of both components is crucial, especially for low-order models that simplify flow characteristics for computational efficiency. Many widely used models today still rely on assumptions established decades ago, reflecting limitations in high-quality experimental data and computational power. This study seeks to improve our understanding of propeller inflow dynamics, providing essential data to refine these foundational models. All results from these measurements can be found in Zarev and Green (2020). [5], which offers a detailed description of the test conditions and wind tunnel setup, along with access to the full dataset. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2025 |
| Provided To Others? | Yes |
| Impact | Only just published. |
| URL | https://www.nwtf.ac.uk/dataset/two-bladed-propeller-performance-in-inclined-flow/ |
| Title | Windsor Automotive Reference Model |
| Description | Carbon dioxide (CO2) plays a significant role in climate change, with passenger vehicles responsible for 12% of CO2 emissions in the European Union. The emission from the Vehicles are directly influenced by aerodynamic drag.This relationship has led to stricter emissions legislation, which is now crucial for manufacturers' competitiveness. Lower drag improves vehicle efficiency and range, benefiting the end user regardless of the powertrain type. Jaguar Land Rover, the sponsor for this work, recognise the impact of legislation on their vehicles and the impact of their vehicles on the environment. Therefore, measurements have been conducted with a specific focus on square back geometries due to their widespread popularity and relevance to the sponsor of this work. The Windsor model, as developed by Steve Windsor of Jaguar Land Rover, is used here has been modified to include a second version with wheels. Further details are given in the paper by Pavia et al. (2020)[1] and Varney (2019)[2]. This model is a good representation of real vehicles (hatchbacks, estate backs or SUVs) without too much simplification such as the Ahmed model. Two configurations of Windsor model are considered for extensive measurements (a) model with no wheels; (b) model with (stationary) wheels. The measurements involve large-scale tomographic Particle Image Velocimetry (PIV), Pressure tappings, and force balance. The full dataset is available from the Loughborough University repository. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2020 |
| Provided To Others? | Yes |
| Impact | This dataset has been used as a reference case in the 2nd, 3rd and 4th Automotive CFD workshops. Around 50 organisations including Universities, industry and SME from Europe, US and Asia have simulated this problem and submitted their solutions for comparison in the workshop. This has led to the improvement of simulation methods for the prediction of automotive flows. This case is used as a tutorial in the Cadence CharLES CFD software. |
| URL | https://www.nwtf.ac.uk/dataset/1709/ |
| Title | Wingtip Vortex structure in Swept-tapered wings |
| Description | Induced drag associated with the wing wake remains a critical concern for the aviation industry. In addition the wingtip vortex poses significant challenges for flight safety, especially in crowded airspace near airports, where take-off and landing can be hazardous, particularly at low altitudes. To mitigate these risks, advancements in wing aerodynamics are necessary to reduce wingtip vortex strength, induced drag, and environmental impact. Understanding the near-field dynamics of wingtip vortices is crucial for designing more efficient wingtip devices, which can help reduce vortex strength and improve safety." Trailing vortices can persist for great distances downstream before dissipating into the atmosphere. Significant efforts have been made to develop theoretical and numerical models for the roll-up process of trailing wingtip vortices. Most experimental investigations have focused on either tracking the mean velocities of the trailing vortex or validating vortex dynamics numerically. These studies have primarily involved wings of simple rectangular planforms[1], examining the formation and development of tip vortices in the near-field. However, limited information is available on the vortex core's structure due to experimental resolution constraints. This study investigates the near-field vortex wake characteristics of a planar wing configuration using stereoscopic particle imaging velocimetry (sPIV) at Re = 1.5 × 106, based on the wing's mean aerodynamic chord. High-resolution, non-intrusive measurements at 200 Hz were conducted to document wake vortex formation and analyze the evolution of tangential and axial velocity distributions, providing essential validation data for numerical simulations. All results from these measurements can be found in Skinner et al. [2], which offers a detailed description of the test conditions and wind tunnel setup, along with access to the full dataset. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2025 |
| Provided To Others? | Yes |
| Impact | Only just published |
| URL | https://www.nwtf.ac.uk/dataset/1462/ |
| Description | Presentation and interactive session at EPSRC UK Turbulence Consortium Annual Meeting 2023 |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Postgraduate students |
| Results and Impact | The presentation was used to introduce the experimental database activity to the community of computational researchers. An interactive Vevox survey was used to help us understand the current use of online experimental wind tunnel data and what requirements the researchers. We used to help design the online data sets. |
| Year(s) Of Engagement Activity | 2023 |
| Description | Presentation and interactive session at National Wind Tunnel Facility Annual Meeting 2023 |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Postgraduate students |
| Results and Impact | The presentation was used to introduce the experimental database activity to the experimental researchers in the National Wind Tunnel Facility. An interactive Vevox survey was used to help us understand how aware experimentalists were of requirements to make data available and the barrier to doing this. This was used to help design the process to capture experimental data. |
| Year(s) Of Engagement Activity | 2023 |
| Description | Presentation and interactive session at UK Fluids annual meeting Swansea, 2024 |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Postgraduate students |
| Results and Impact | The presentation was used to introduce the experimental database activity to the EPSRC Fluids network meeting, mainly PhD students. An interactive Vevox survey was used to help us understand the current use of online experimental data and what requirements the researchers have to publish. This was aimed at improving the amount of data made publicly available. |
| Year(s) Of Engagement Activity | 2024 |