The Effects of Split Drag Flaps on Directional Motion of UiTM’s BWB UAV Baseline-II E-4: Investigation Based on CFD Approach

2012 ◽  
Vol 433-440 ◽  
pp. 584-588 ◽  
Author(s):  
Firdaus Mohamad ◽  
Wisnoe Wirachman ◽  
Wahyu Kuntjoro ◽  
Rizal E M Nasir
Keyword(s):  
Force Coefficient ◽  
Side Force ◽  
Moment Coefficient ◽  
Dimensionless Coefficient ◽  
Directional Motion ◽  
Aerial Vehicle ◽  
Blended Wing Body ◽  
Control Surfaces ◽  
Side Force Coefficient ◽  
Linear Trends

This paper presents a study about split drag flaps as control surfaces to generate yawing motion of a blended wing body aircraft. These flaps are attached on UiTM’s Blended Wing Body (BWB) Unmanned Aerial Vehicle (UAV) Baseline-II E-4. Deflection of split drag flaps on one side of the wing will produce asymmetric drag force and, as consequences, yawing moment will be produced. The yawing moment produced will rotate the nose of the BWB toward the wing with deflected split drag flaps. The study has been carried out using Computational Fluid Dynamics to obtain aerodynamics data with respect to various sideslip angles (ß). The simulation is running at 0.1 Mach number or about 35 m/s. Results in terms of dimensionless coefficient such as drag coefficient (CD), side force coefficient (CS) and yawing moment coefficient (Cn) are used to observe the effects of split drag Subscript text flaps on the yawing moment. All the results obtained shows linear trends for all curves with respect to sideslip angles (ß).

scholarly journals Influence of Rectangular Strips’ Size on Aerodynamic Performance of a High-Speed Train Subjected to Crosswind

2021 ◽  
Author(s):  
Mengying Wang ◽  
Zhenxu Sun ◽  
Shengjun Ju ◽  
Guowei Yang
Keyword(s):  
High Speed ◽  
Aerodynamic Performance ◽  
Design Parameters ◽  
Orthogonal Experimental Design ◽  
High Speed Train ◽  
Force Coefficient ◽  
Roll Moment ◽  
Side Force ◽  
Moment Coefficient ◽  
Side Force Coefficient

Abstract Conventional studies usually assume that the train surface is smooth, so as to simplify the numerical calculation. In fact, the surface of the train is irregular, which will change the flow characteristics in the boundary layer and further affect the aerodynamic performance of a train. In this work, roughness is applied to the roof of a 1:25 scaled train model in the form of longitudinal strips. Firstly, the improved delayed detached eddy simulation (IDDES) method is adopted to simulate the aerodynamic performance of the train model with both smooth and rough surface, which are subjected to crosswind. Results show that the side force coefficient and the roll moment coefficient subjected to rough model decreased by 3.71% and 10.56% compared with the smooth model. Then, the width, height and length of the strips are selected as variables to design different numerical simulation schemes based on the orthogonal experimental design method. Through variance analysis, it can be found that four design parameters have no significant effect on the side force coefficient. Meanwhile, for the roll moment coefficient, the length of the strips in the straight region of the train has a significant effect and the width of the strips has a highly significant effect on it. These conclusions can provide a theoretical basis to improve the aerodynamic performance of the high-speed train subjected to crosswind.

Numerical Simulation Analysis of Car Overtaking on SST Turbulence Model

2014 ◽  
Vol 628 ◽  
pp. 270-274
Author(s):  
Yi Bin He ◽  
Qi Zhi Shen
Keyword(s):  
Numerical Simulation ◽  
Numerical Experiment ◽  
Drag Coefficient ◽  
Turbulence Model ◽  
Simulation Analysis ◽  
Turbulence Models ◽  
Force Coefficient ◽  
Side Force ◽  
Sst Turbulence Model ◽  
Side Force Coefficient

Thebased SST (shear strain transport) turbulence model combines the advantages of and turbulence models and performs well in numerical experiment. In the paper, the SST turbulence model is applied to model vehicle overtaking process with numerical simulation technology. The change graph of drag coefficient and side force coefficient are gained. Analysis of the phenomena is presented at the end.

EFFECT OF SILICA LOADING AND COUPLING AGENT ON WEAR AND FATIGUE PROPERTIES OF A TREAD COMPOUND

2018 ◽  
Vol 92 (2) ◽  
pp. 326-349 ◽  
Author(s):  
Harini Sridharan ◽  
Abhilash Guha ◽  
Sanjay Bhattacharyya ◽  
Anil K. Bhowmick ◽  
R. Mukhopadhyay
Keyword(s):  
Crack Growth ◽  
Coupling Agent ◽  
Abrasion Resistance ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Force Coefficient ◽  
Side Force ◽  
Tan Δ ◽  
Side Force Coefficient

ABSTRACT The effects of highly dispersible silica and the nature of silane in a tire tread cap compound were studied with particular reference to dynamic mechanical properties, abrasion resistance, side force coefficient, and fatigue crack growth (FCG) properties. The rubber matrix chosen was a blend of solution grade styrene butadiene rubber and polybutadiene rubber. Six different loadings of silica were used. Bistriethoxysilylpropyltetrasulfide (S) was taken as the coupling agent. In addition, the potential of two new generation silanes, 3-octanoylthio-1-propyltriethoxysilane (N) and 3-mercaptopropyl-di [tridecan-1-oxy-13-penta ethyleneoxideethoxysilane] (V) was also explored at 70 phr silica loading. Optimum properties were obtained at 50 phr loading of silica (S50). The tensile moduli for the compounds increased sharply with silica loading. Higher values of tan δ, indicating higher hysteresis, were obtained in compounds containing higher filler dosage. However, enhanced abrasion resistance and side force coefficient were observed at higher loadings of silica due to an increased reinforcement phenomenon. The crack growth exponent (β) was lowest for S50. Among the silanes tested, V showed a 22% drop in tan δ at 70 °C, 11% drop in abrasion loss, and an increase in FCG rate. N exhibited a lower FCG rate as compared with the silane S.

Side Force Coefficient Evaluation of a Commercial Bus with Vortex Generators

2019 ◽  
Author(s):  
Daniel Garcia Ribeiro ◽  
Juan Flores Mezarina ◽  
Pedro David Bravo-Mosquera ◽  
Hernán Cerón-Muñoz ◽  
John Jairo Vaca-Rios
Keyword(s):  
Vortex Generators ◽  
Force Coefficient ◽  
Side Force ◽  
Side Force Coefficient

Lateral-Directional Aerodynamics of a Canard Guided Spin Stabilized Projectile at Supersonic Velocity

2011 ◽  
Vol 110-116 ◽  
pp. 4343-4350 ◽  
Author(s):  
Xiu Ling Ji ◽  
Hai Peng Wang ◽  
Shi Ming Zeng ◽  
Chen Yang Jia
Keyword(s):  
Computational Study ◽  
Cfd Modeling ◽  
Aerodynamic Coefficients ◽  
Force Coefficient ◽  
Modeling And Analysis ◽  
Moment Coefficient ◽  
Computational Fluid Dynamics Cfd ◽  
Spinning Projectile ◽  
Yaw Moment ◽  
Side Force Coefficient

A computational study performed for a canard guided spin stabilized projectile using finite volume TVD schemes is described in this paper. Computational Fluid Dynamics (CFD) modeling and analysis of the spinning projectile with fixed canard are conducted to determine the lateral-directional aerodynamic coefficients at three supersonic speeds and various angles of attack. The analyses provide a detailed understanding of the effects of canard with different circumferential position on lateral-directional aerodynamic coefficients, and the results show that side force coefficient and yaw moment coefficient vary periodically with the circumferential position angles of canard.

scholarly journals Spectral Techniques Applied to Evaluate Pavement Friction and Surface Texture

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 424
Author(s):  
Yuan Yan ◽  
Maoping Ran ◽  
Ulf Sandberg ◽  
Xinglin Zhou ◽  
Shenqing Xiao
Keyword(s):  
Spectral Analysis ◽  
Surface Texture ◽  
Spectral Band ◽  
Force Coefficient ◽  
Spectral Techniques ◽  
Side Force ◽  
Texture Parameters ◽  
Texture Characteristics ◽  
Pavement Friction ◽  
Side Force Coefficient

To study texture of pavement surfaces and its effect on pavement friction, this article features a field experiment conducted on in-service pavements to characterize surface texture by spectral analysis to substantiate links to friction values. Pavement friction was measured using a Mu-meter and British pendulum tester whereas texture data was collected using a stationary laser profilometer. Texture spectra were analyzed and expressed in third octave bands. The correlation between texture spectral levels and friction values at different speeds are discussed in the paper. Results show that the texture level, including spectral band levels, can well represent texture characteristics, as texture spectral levels have a good correlation with friction coefficient, especially the texture level of texture wavelengths at 1.25–12.5 mm versus SFCsl (representing the slope of the side force coefficient (SFC) versus speed), i.e., the slope of friction versus speed. This friction parameter gives better correlations with texture parameters than friction values at different speeds, which is believed to be an effect of the drainage caused by texture in that wavelength range.

Wind Loading on Articulated Trailers During Tipping

1995 ◽  
Vol 209 (2) ◽  
pp. 103-110
Author(s):  
H Fessler ◽  
T H Hyde ◽  
W Sun
Keyword(s):  
Reynolds Number ◽  
Lateral Force ◽  
The Body ◽  
Scale Model ◽  
Wind Loading ◽  
Wind Force ◽  
Force Coefficient ◽  
Side Force ◽  
Side Force Coefficient ◽  
Lateral Area

Modern articulated trucks have very large trailers, up to 11 m long. When they empty their load, the body may be inclined at up to 40° this causes a high obstruction to sideways winds, which may cause the vehicle to roll over. The lateral force and the roll-over moment were measured in wind tunnel tests of a 1/60 scale model of a typical truck with the body at different tipping angles, ψ, and the wind in different directions, α. The side force coefficient was found to be approximately 1.5, almost independent of ψ, α up to 15° and Reynolds number up to 340000. The resultant of the wind force was found to act at almost the same height above the ground as the centroid of the lateral area for all values of ψ.

Sign in / Sign up

Export Citation Format

Share Document