Mechanical Engineering Literature Review: Solar Car Aerodynamics

This literature review synthesizes various studies on the aerodynamic design and analysis of solar-powered vehicles. It begins with Doig and Beves' work on the Sunswift IV, detailing their use of CATIA and ANSYS Fluent to minimize drag. Subsequent studies by Abinesh and Kalidasan, Majdandzic et al., Villaizan et al., Vinnichenko et al., Paterson et al., Smith et al., Varun et al., Govardhana and Reddy, and Taha et al. are examined. These studies explore CFD simulations, the impact of roughness, optimization of cooling, and the overall design and development of solar vehicles. The review highlights methodologies like RANS equations, the importance of pressure coefficients, the role of battery selection, and the influence of solar cell placement. Overall, the review emphasizes the ongoing efforts to enhance the efficiency and performance of solar cars through aerodynamic design and analysis.

Literature review
Doig and Beves in 2014 studied aerodynamic design and development of the Sunswift IV
solar racing car. The project was initiated by the students under the guidance of professor
Doig and Bees, from the initial sketches to the final vehicle. They analysed the shape of the
vehicle, they also modified the shape of the final vehicle using computational fluid dynamics
simulations. They targeted their study towards minimizing the coefficient of drag acting on
the vehicle. They adopted numerical methodology to solve the problem. They utilized
CATIA software for modeling the geometry of the solar powered vehicle and ANSYS Fluent
version 6.3 for computation fluid dynamics simulation. The meshing adopted by them was
very fine in curved and complex geometries when compared to the other parts of the
geometry as shown in figure 1. Solar car designed by them won the World Solar Challenges
in year 2009 and 2011. Car developed by them also hold the fastest solar powered car
Guinness World Record [1].
Figure 1 Meshed geometry of the solar powered car [1]
Abinesh and Kalidasan in 2016 reviewed the studies conducted in the field of solar electric
vehicles [2]. Majdandzic et al in 2018 conducted aerodynamics design of solar road vehicle.
They conducted computational fluid dynamics study of the solar road vehicle to analyse the
flow characteristics and aerodynamics forces. They considered RANS (Reynolds Average
Navier Stokes) equation with k-ω turbulence modeling method to solve the steady viscous
flow problem. From their computational study they found that drag force due to viscosity

plays a major part (41%) in the acting forces on the vehicle. From their study they found that
when the value of pressure coefficients is large at the top surface results in increment of the
downward force thus vehicle traction. From their study they also concluded that it is essential
to consider the roughness while designing as it results in large fuel consumption when outer
surfaces of the vehicle are not smooth or rough [3].
Villaizan et al in 2014 conducted analysis and design of an electrical vehicle powered by
photovoltaic panels. They utilized computational fluid dynamics simulation methodology to
solve the geometry of the vehicle to analyse the generated drag force. To model the geometry
they utilized CAD software and to analyse the geometry they utilized SolidWorks Flow
simulation software. Conditions considered by them are shown in table 1.They also targeted
their study towards the optimization of the cost due to the Li-ion battery. They concluded that
AGM (absorbent glass mat) battery is the best choice when working with solar photovoltaic
panels. They concluded that the vehicle designed by them can work properly if there is
limited resistance force [4].
Table 1 Values of the parameters [4]
S.N. Parameter Value
1. Fluid type Air
2. Flow type Laminar-turbulent
3. Pressure 74.66 [KPa]
4. Temperature 293 [K]
5. X-direction speed 60 [km/h]
6. Y-direction speed 0 [m/s]
7. Turbulence intensity factor 1/100
8. Roughness at the surface 0.001 [m]
Vinnichenko et al in 2014 conducted solar car aerodynamic design for optimal cooling and
high efficiency. They analysed temperature of solar cell mounted on the surface by forced
convection cooling for two solar car geometries. To analyse the temperature of solar cell they
solved heat balance equation by considering appropriate boundary conditions. They targeted
their study towards not only to reduce the drag coefficient but also to reduce the overall
removal of heat from the photovoltaic to enhance its power generation capability. They also
conducted the experiments to validate their results. They concluded that the region where the
solar photovoltaic cells are placed can also influence the overall efficiency of the system [5].
Paterson et al in 2016 conducted design and development of the Sunswift eVe solar vehicle.
The solar vehicle developed by them consists two seats, is capable of running at 130km/h
with battery capacity of 16 kWh. The solar vehicle developed by them is shown in figure 2.
They utilized CATIA for the geometrical modelling of the solar vehicle and computational
fluid dynamics for the simulation and analyses purpose considering suitable type of boundary
conditions and turbulence effect. They utilized carbon fiber composite material to
manufacture the solar car. The solar powered vehicle developed by them can run up to 500km
continuously in one run without supply of any extra power [6].

Figure 2 Solar powered vehicle [6]
Smith et al in 2018 discusses about the journey of the UNSW solar car team. They told that
UNSW was first developed in 1995 and till now is working and has achieved tremendous
amount of success in the field of solar photovoltaic cell powered vehicle. Their team has
achieved success in terms of the speed, battery power, battery capacity flexibility and more.
They discussed that the project was majorly implemented and run by the students’ team [7].
Varun et al in 2018 conducted computational fluid dynamics analyse of aerodynamics of the
car. They targeted their study towards minimising the drag due to aerodynamics of the car by
analysing the nearby flow filed of vehicle. They utilized CATIA version 5 to do the
geometrical modelling of the solar vehicle and ANSYS Fluent version 14.5 for analysis of the
flow filed. They considered k-epsilon steady state modeling method to analyse the
aerodynamic of the vehicle [8].
Govardhana and Reddy in 2014 estimated lift and drag coefficient using computational fluid
dynamics analysis on an Ahmed body. Ahmad body geometry is very simple and is analysed
utilizing the finite volume method. They utilized CATIA version 5 for the geometric
modeling, than they imported the geometry into the GAMBIT software for the meshing. They
utilized fine meshing in the areas where geometry shape was irregular, curvy and complex.
They utilized 25̊ hatchback and k – epsilon turbulence modeling. They found 0.399 and 1.146
coefficient of lift and drag respectively by their analysis [9].
Taha et al in 2011 conducted computational fluid dynamics analysis of Merdeka 2 solar
vehicle. They numerically studied the aerodynamics characteristics of the solar vehicle based
on the vehicle frontal area. They utilized Fluent tool of the ANSYS to conduct the CFD
simulations. They found coefficient of drag to be equal to 0.35. They also compared their
results with the experimental results and found very slight difference [10].
References
[1]. G. Doig and C. Beves, “Aerodynamic design and development of the Sunswift IV solar
racing car”, International Journal of Vehicle Desing, vol. 66, no. 2, pp. 144-167, 2014.
[2]. D. T. Abinesh and B Kalidasan, “A review on solar electric vehicle”, Imperial
International Journal of Eco-friendly Technologies, vol. 1, no. 1, pp. 80-83, 2016.

[3]. L. Majdandzic, D. Buljic, A. Buljac and H. Kozmar, “Aerodynamic design of a solar
road vehicle” , International Journal of Automotive Technology, vol. 19, no. 6, pp. 949-
957, 2018.
[4]. J. A. Villaizan, C. A Pineda C. and R. J. Ramos, “Analysis for the design of a uni-
personal electric vehicle prototype with photovoltaic panels”, IEEE.
[5]. N. A. Vinnichenko, A. V. Uvarov, I. A. Znamenskaya, H. Ay and T-H Wang, “Solar
car aerodynamic design for optimal cooling and high efficiency”, Solar Energy, vol.
103, pp. 183-190, 2014.
[6]. S. Paterson, P. Vijayaratanam, C. Parera and G. Doig, “Desing and development of the
sunswift eVe solar vehicle: a record breaking electric car”, Journal of Automobile
Engineering, pp. 1-15.
[7]. H. C. Smith, S. Paterson, C. Mazzone, S. Diasions and G. Doig, “20 Years of UNSW
Australia's Sunswift Solar Car Team: A New Moment in the Sun, but Where to Next?”,
SAE Technical paper, 2015.
[8]. R. Varun, S. Sankar, R. Varma and K. V. Sreejith, “CFD analysis of aerodynamics of
car”, International Journal of Innovation Research in Science, Engineering and
Technology, vol. 7, no. 5, pp. 4689-4693, 2018.
[9]. M. Govardhana and B. V. Reddy, “Estimation of drag and lift o Ahmed body using
CFD analysis”, International Journal of Advanced and Innovative Research, vol. 3, no.
8, pp. 51-55, 2014.
[10]. Z. Taha, R. Passarella, Sugiyono, N. A. Rahim, J. M. Sah and A. H. Yazid, “CFD
analysis of Merdeka 2 solar vehicle”, Advanced Science Letters, vol. 4, no. 8/9/10, pp.
2807-2811, 2011.