Flow Behaviour Analysis Inside A Helmet
Abhishek Pushkar1, Kunal Mehra2, Sahil Verma3, Chanakya Rajan4
UG Student1,2,3,4, Department of Mechanical Engineering, JIMS Engineering Management Technical Campus,
Greater Noida, Uttar Pradesh, India.
Ashutosh Singh5, Dhruv Kumar6
Assistant Professor5,6, Department of Mechanical Engineering, JIMS Engineering Management Technical Campus,
Greater Noida, Uttar Pradesh, India.
Devendra Jha7
Professor7, Department of Mechanical Engineering, JIMS Engineering Management Technical Campus,
Greater Noida, Uttar Pradesh, India
Abstract
A helmet is a defensive object used by riders for head
protection against injuries caused by road accidents. In this
paper, a standard helmet is designed using SolidWorks 2018.
The parametric based analysis is performed on the helmet
using SolidWorks Flow Simulation Tool. Parameters like
shear stress, vorticity, velocity, pressure, acoustic power and
temperature are assessed. Measured values obtained are
utilized to survey the defensive execution of the helmet.
Through the results, a comfortable as well as
protective structure of helmet can be planned and designed.
Keywords: Helmet, Shear stress, Flow Simulation, Vorticity,
Velocity, Temperature, Pressure.
Introduction In today’s world, the most common mode of transportation is
two-wheelers. We can find one in nearly every household
nowadays. Besides this, it is also used in Racing as a sport.
Head injuries as a consequence of road accidents are one of
the main reasons of death and disability among people. A
helmet decreases this danger of head and cerebrum wounds by
diminishing the effect of impact to the head.
During an impact, helmet works in a three-step mechanism:
1. It decreases the deceleration of the skull, and
consequently the cerebrum development, by directly
dealing with the effect. The delicate material
consolidated in the helmet assimilates a portion of the
effect and consequently, the head stops all the more
gradually. This implies the cerebrum does not hit the
skull with such extraordinary power. 2. It spreads the powers of the effect over a more
noteworthy surface zone with the goal that they are not
focused on specific territories of the skull. 3. It counteracts direct contact between the skull and the
affecting item by going about as a mechanical
boundary between the head and the article.
Figure 1: Parts of a helmet
In addition to meeting the antecedently delineated functions
and conforming to standards, a helmet must be designed to
suit the native weather and traffic conditions. The subsequent
unit covers few aspects typically addressed by helmet
designers:
1. Materials utilized in the development of a helmet
should not deteriorate due to weather change, should not
be harmful or cause hypersensitive responses and should
have a good life. Right now, the plastic materials regularly
used are Expanded Poly-Styrene (EPS), Acrylonitrile
Butadiene Styrene (ABS), Poly Carbon (PC) and Poly
Propylene (PP). While the material of the cap shell, for the
most part, contains PC, PVC, ABS or Fiberglass; the
crushable liner inside the shell is frequently made out of
EPS – a material that can assimilate stun and sway and is
generally economical. However, helmets with EPS liners
are required to be disposed off after an accident, and
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 14, Number 10, 2019 (Special Issue) © Research India Publications. http://www.ripublication.com
Page 155 of 159
regardless of this, clients need to replace such helmets
after 3-5 years of usage.
2. Gauges regularly set the base inclusion of a helmet.
Half-head helmet offers negligible inclusion. Full-
face helmet guarantees that the wearer's fringe vision
and hearing are not traded off.
Literature Review
S.K. Biswal, S.M. Shahrukh Rais, K. Krishna considered
two materials – Acrylonitrile Butadiene Styrene (ABS) and
Poly Vinyl Chloride (PVC) for dynamic analysis of helmet.
They designed the helmet using CATIA V5.0 and did the
Impact test analysis using ANSYS software. They compared
Von Misses Stresses, Strain and Deformations of ABS and
PVC at 50, 60 & 70 km/h in front, right and back directions.
They concluded that PVC plastic material is better than ABS
in terms of stresses developed. So, if the shell part is made
using PVC, then it would be able to withstand large stresses.
However, ABS material is preferred over PVC to provide
lesser deformations during accidents.
V.C. Sathish Gandhi, R. Kumaravelan, S. Ramesh, M.
Venkatesan, M. Ponraj carried out the investigation of
Motor Cycle Helmet under Static and Dynamic Loading. The
Design and Investigation of head protector were done in
ANSYS software for both static and dynamic conditions.
S. Irfan Sadaq, Md. Abdul Raheem Junaidi, V. Suvarna
Kumar, Joseph George, Konnully,
Sirajuddin Qadiri completed Impact Test on Motor Cycle
Helmet for Different Impact edges using FEA. A limited
component demonstration depending on practical geometric
highlight of a bike helmet was set up, and a component,
COSMOS, was used to reproduce dynamic reactions at
various effect speeds.
V.C. Sathish Gandhi, R. Kumaravelan, S. Ramesh, M.
Venkatesan, M. Siva Rama Krishnan designed a helmet
using the concept of streamline shape with antiglare visor. In
this paper, they concluded that, for reducing the neck pain of a
rider after long traveling, we should use streamlined shape
helmet. Whereas, the polymer coated visor reduces the glare
and eliminates the opposite headlight glare during night
ridings in a better way as compared to the noncoated visor.
P. Viswanadha Raju, Vinod Banthia, Abdul Nassar,
Designed a Streamlined Motorcycle Helmet with Enhanced
Head Protection. Fluid stream investigations were completed
to review the stream conduct inside a helmet and alterations
were proposed to improve the stream inside the helmet to
provide more comfort to the rider. Effect examination was
done to check if the adjusted cap meets the BIS sway retention
test particular.
Methodology
The entire model was designed in Dassault systems
Solidworks, and the analysis was done in Solidworks Fluid
Simulation. The process of designing involved various
degrees of surface and solid modeling. Most important of
which included the freeform surface modeling tools which
were used to give the curvature and shape of the design. The
design utilizes the dimensions specified in the following
diagram.
Figure 2: 2D Drawing of the Helmet with Different Views
and Dimensions
Furthermore, as the helmet is subjected to various flow
simulations as in the case of it being used, it has to be
subjected to the flow of air. The flow of air is limited to a
speed of 100Km/hr since this is the most common and the
most frequent speed at which it is used. Both steady state and
transient analysis were carried out.
Figure 3: 3D Model of the helmet
Figure 4: Computational Domain
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 14, Number 10, 2019 (Special Issue) © Research India Publications. http://www.ripublication.com
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Results and Discussions
From our simulation, the following results were observed in
the model :
Figure 5: Flow Trajectories
From Fig. 5, we can see the various flow trajectories of the air
flow. As observed, we can see a small amount of air is
forming a vortex feature at two points i.e. inside and behind
the flow model. This called for further vorticity analysis
which is discussed further in the project.
Figure 6(a): Side View Velocity
Figure 6(b): Top View Velocity
Figure 6(c): Front View Velocity
Fig 6(a, b, c), represents the flow speeds in different axes. The
maximum and minimum speed of flow for side, top and front
view are (36.857 m/s, 1.204 m/s), (33.023 m/s, 1.215 m/s) and
(37.153 m/s, 1.216 m/s) as shown in the figure respectively.
Figure 7: Temperature
Fig. 7, represents the various temperature regions developed
as a result of flow alone. It was observed that the internal
regions were heated by a certain temperature. Also, it was
noteworthy to note there are also certain regions where the
temperature is reduced. The maximum and minimum values
of temperature are 20.42 0C, and 19.75 0C respectively.
Fig. 8, represents the various regions of acoustic effects
created i.e. the maximum noise regions and their region of
effect. The entire effect created is because of flow only. The
maximum and minimum values are 0 dB and 49.53 dB.
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 14, Number 10, 2019 (Special Issue) © Research India Publications. http://www.ripublication.com
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Figure 8: Acoustic Power
Fig. 9 represents the various shear stress regions and their
distribution on the surface of the helmet in various views. The
maximum i.e. 3.09 Pa and minimum i.e. 0.09 Pa regions of
shear stresses are seen from the image. The frontal region has
the maximum interaction with air and thus suffers from
maximum shear effects.
Figure 9: Shear Stress Analysis At Different Face Of Helmet
(Front, Back, Right, Isometric, Top & Bottom)
The group of pictures shown below i.e. Fig. 10 (A, B, C, D, E,
F, G) represents the vorticity and Table 1 represents the
maximum and minimum vorticity of the flow in rotations per
seconds at different positions.
Figure 10: Vorticity side view
(A) INITIALLY (B) JUST BEFORE CONTACT
(C) DUAL VORTEX (D) MAXIMUM CONTACT
(E) POST CONTACT (F) VORTEX SUBSIDING
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 14, Number 10, 2019 (Special Issue) © Research India Publications. http://www.ripublication.com
Page 158 of 159
Positions
Maximum
Vorticity
(1/s)
Minimum
Vorticity
(1/s)
Initial 11.25 1.30
Just Before Contact 125.17 0.97
Dual Vortex 108.78 0.76
Maximum Contact 419.46 0.86
Post Contact 225.53 1.20
Vortex Subsiding 73.66 0.77
Table 1: Maximum & Minimum Vorticity
Fig.11 represents the various pressure regions and their
distribution on the surface of the helmet in various views. The
maximum i.e. 1.09 atm and minimum i.e. 0.99 atm regions of
pressure are front and side of the helmet respectively as
shown in the image. The frontal region has the maximum
interaction with air and thus suffers from maximum pressure
force. There is some weight also applied on the due helmet
mass and gravity which is under consideration for the
analysis.
Figure 11: Pressure Contours at different faces of helmet
(Front, Back, Left, Isometric, Top & Bottom)
Conclusion
Fluid flow Analyses were carried out in SolidWorks to study
the flow behavior inside a helmet and results were discussed
to improve the flow within the helmet to improve the comfort
of the rider. The following points were concluded: -
Vortices generated in the region between chin guard
and face due to insufficient air flow which results in
exhaled air recirculation, which may cause discomfort
to the rider. This can be improved by proper ventilation
at the front side.
The maximum and minimum speed of flow for side,
top and front view are (36.857 m/s, 1.204 m/s), (33.023
m/s, 1.215 m/s) and (37.153 m/s, 1.216 m/s)
respectively.
The temperature variation in the helmet was too small.
Similarly, noise creation inside the helmet was not so
problematic.
When we talk about shear stress and pressure force
then we see that the frontal region has the maximum
interaction with air and thus suffers from maximum
shear effects as well as maximum pressure force.
References [1] S.K. Sharma “ Objective Zoology ” 19th edition 2008 p.p
3.291-3.293
[2] B D Chaurasia “ Human Anatomy, vol-3 Head And Neck Brain ” 5th edition 2010, p.p 3-49.
[3] Gandhi, V.S., Kumaravelan, R., Ramesh, S., Venkatesan, M. and Ponraj, M.R., 2014. Performance Analysis of Motor Cycle Helmet under Static and Dynamic Loading. Mechanics and Mechanical Engineering, 18(2), pp.85-96.
[4] Raju, P.V., Vinod, B. and Abdul, N., 2009. Design of streamlined motorcycle helmet with enhanced head protection. SASTech J, 8(2), pp.1-8.
[5] Sadaq, S.I., Junaidi, A.R., Kumar, V.S., Konnully, J.G. and Qadiri, S.S., Impact Test on Motor Cycle Helmet for Different Impact angles using FEA. International Journal of Engineering Trends and Technology.[Online], 12(6), pp.278-281.
[6] Gandhi, V.S., Kumaravelan, R., Ramesh, S., Venkatesan, M. and Krishnan, M.S.R., 2014. An Aerodynamic Design and Analysis of Motor Cycle Helmet with Anti-Glare Visor. World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, 8(3), pp.628-631.
[7] Saroj Kumar Biswal, S.M.Shahrukh Rais, Karanamkrishna,2016, Impact test analysis on a 2-wheeler helmet using 3D modeling and analyzing software for two different materials. International Journal of innovative research in technology, pp. 249-253.
[8] Google Image https://www.bestbeginnermotorcycles.com/ultimate-motorcycle-helmet-guide/helmet-protective-diagram/
[9] Mills, N.J. and Gilchrist, A., 2008. Finite-element analysis of bicycle helmet oblique impacts. International Journal of Impact Engineering, 35(9), pp.1087-1101.
[10] Chang, L.T., Chang, G.L., Huang, J.Z., Huang, S.C., Liu, D.S. and Chang, C.H., 2003. Finite element analysis of the effect of motorcycle helmet materials against impact velocity. Journal of the Chinese Institute of Engineers, 26(6), pp.835-843.
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 14, Number 10, 2019 (Special Issue) © Research India Publications. http://www.ripublication.com
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