Hybrid journal (It can contain Open Access articles) ISSN (Print) 1743-5447 - ISSN (Online) 1743-5455 Published by Inderscience Publishers[450 journals]
Authors:Lennert Sterken, Simone Sebben, Lennart Löfdahl Pages: 1 - 17 Abstract: This paper aims to investigate the sensitivity of the rear-end design to the yaw response of a passenger vehicle. To accomplish this, rear-end extensions are attached to the base perimeter of a sport utility vehicle (SUV). The intention of the extensions is to improve and to smooth out the pressure recovery such that a more stable wake is created. The extensions facilitate the implementation of configuration changes with respect to design, inclination angle and length. To control the separation conditions of the flow entering the near-wake, two different designs are studied. The yaw response is analysed through the global forces and flow field measurements presented as surface pressure distributions and wake plane measurements of local drag. The results show that the rear-end can be designed as to control the yaw response so the aerodynamic drag is minimised and passenger vehicle stability is maintained. Keywords: full-scale wind tunnel experiments; yaw response; drag reduction; rear-end stability; rear-end design Citation: International Journal of Aerodynamics, Vol. 7, No. 1 (2020) pp. 1 - 17 PubDate: 2020-05-06T23:20:50-05:00 DOI: 10.1504/IJAD.2020.107165 Issue No:Vol. 7, No. 1 (2020)
Authors:M. Hafez, A. Chuen, A. Burkhead Pages: 18 - 35 Abstract: The hyperbolic systems of equations describing the shallow water surface waves are solved numerically using finite difference schemes and an explicit time integration procedure. The equations are similar to isentropic Euler equations (with γ = 2) and can be simplified using a potential flow model. The results of isentropic Euler, potential model, transonic small disturbance, and full Euler equations are compared for typical flows around pointed and blunt bodies for several Mach numbers. On the other hand, water table experiments are described and the flow over obstacles is studied. Using the theory of hydraulic analogy, the relations between compressible flows and shallow water surface waves are discussed. Flow patterns, including formation of shock waves and expansion fans are presented. It is demonstrated that the water table can be an inexpensive educational tool for demonstration of transonic and supersonic flow phenomena. Keywords: hydraulic analogy; computer simulations; shallow-water surface waves; water tables; experimental results Citation: International Journal of Aerodynamics, Vol. 7, No. 1 (2020) pp. 18 - 35 PubDate: 2020-05-06T23:20:50-05:00 DOI: 10.1504/IJAD.2020.107159 Issue No:Vol. 7, No. 1 (2020)
Authors:Umberto Ravelli, Marco Savini Pages: 36 - 60 Abstract: The main purpose of this numerical study is to assess the capability of OpenFOAM in predicting aerodynamic performance of blunt and slender devices for automotive and motorsport applications such as a diffuser-equipped blunt body and a F1 single element front wing in ground effect. Reynolds Averaged Navier-Stokes (RANS) simulations were carried out at different values of ride height and diffuser angle/angle of attack: predictions of integral quantities, such as drag (CD) and lift (CL) coefficients were validated against the available set of experimental data from Loughborough and Southampton Universities. Results put in evidence that OpenFOAM is suitable for fulfilling the goal of this study, even if the entire workflow (from meshing to calculation) is not user-friendly: the success of the simulations strongly depends on quality of the mesh, turbulence model, type of solver and numerical setup. Keywords: open-source; OpenFOAM; CFD; aerodynamics; ground effect; motorsport; automotive; diffuser; blunt body; wing; ride height; Reynolds Averaged Navier-Stokes; RANS Citation: International Journal of Aerodynamics, Vol. 7, No. 1 (2020) pp. 36 - 60 PubDate: 2020-05-06T23:20:50-05:00 DOI: 10.1504/IJAD.2020.107161 Issue No:Vol. 7, No. 1 (2020)
Authors:Rowayne E. Murzello, Mehdi Nazarinia, Amanda J. Hughes Pages: 61 - 82 Abstract: Solar powered unmanned aerial vehicles (SPUAV) have numerous applications and are considered as environmentally friendly vehicles since they only use sun's energy for propulsion. In this study, a conceptional design was proposed which integrates a cooling duct inside the airfoil to provide cooling for the backside of solar cells at Reynolds number of 206,000 at an altitude of 1 km. Duct dimensions were first optimised using a MATLAB program. Computational fluid dynamics (CFD) was used to investigate the lift and drag characteristics of the modified airfoil. Heat transfer analysis on the solar array using CFD was performed to obtain solar cell temperatures of the baseline and modified design. Results obtained from the cruising conditions showed that the maximum temperature drop was 3°C and the cooling duct increased the lift force by 9% per metre with an increase in drag of 13%. Keywords: cooling duct; computational fluid dynamics; CFD; unmanned aerial vehicle; solar powered UAV; heat transfer enhancement; solar cell Citation: International Journal of Aerodynamics, Vol. 7, No. 1 (2020) pp. 61 - 82 PubDate: 2020-05-06T23:20:50-05:00 DOI: 10.1504/IJAD.2020.107162 Issue No:Vol. 7, No. 1 (2020)
Authors:Rowayne E. Murzello, Mehdi Nazarinia, Amanda J. Hughes Pages: 83 - 88 Abstract: In this note, an attempt at giving as simple as possible an explanation for the lift of an airfoil is proposed based on an intuitive use of Newton's law on one hand and the application of the well-established inviscid flow theory of thin airfoils on the other. A thin parabolic cambered plate is chosen as profile at zero incidence because the flow it produces minimises viscous effects and the particle paths along the plate, above and below it, have the same length, thus proving the 'equal transit' explanation to be wrong. Keywords: flow past profiles; Newton's law; thin airfoil theory; viscous effects; airfoil lift; leading edge adaption; Kutta-Joukowski condition; Reynolds number Citation: International Journal of Aerodynamics, Vol. 7, No. 1 (2020) pp. 83 - 88 PubDate: 2020-05-06T23:20:50-05:00 DOI: 10.1504/IJAD.2020.107176 Issue No:Vol. 7, No. 1 (2020)
Hybrid journal (It can contain Open Access articles)
