Icfd14 Eg 7S05
Icfd14 Eg 7S05
Icfd14 Eg 7S05
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ICFD14-EG-7S05
ABSTRACT I. INTRODUCTION
Engine produces a high amount of heat while Radiators are used in automobiles to transfer heat
running, which is about one-third of the total from the engine coolant to ambient air. Insufficient heat
power. This heat can raise the engine temperature dissipation can result in the overheating of the engine,
to a very high level and damage or seize the engine which leads to the breakdown of lubricating oil, metal
components. Hence, for the safety of the engine weakening of engine parts, and significant wear
components, it needs to run at much lower between engine parts. To minimize the stress on the
temperature, which is called engine working engine as a result of heat generation, automotive
temperature. radiators must be redesigned to be more compact while
Radiator plays a vital role in engine cooling still maintaining high levels of heat transfer
system. It is important to determine mass flow rate performance. Despite the name, most radiators transfer
of the cooling water as a function of the crank shaft bulk of their heat via convection. The demand to
rotational speed. Thus, the present study concerns enhance the heat transfer rate can be addressed either
many parameters to have a complete overview on by increasing the surface area or by increasing the
the radiator operation. These parameters include convective heat transfer coefficient. With regard to
the heat rejected from the engine to the cooling higher surface area, many types of compact heat
water as a function of crank shaft rotational speed, exchangers have been proposed. In order to increase the
the mass-flow rate of air through the radiator core convective heat transfer coefficient, innovative heat
as a function of the car speed, static pressure drop transfer fluids are required, for which, conventional
of the air across the radiator core at varying air heat transfer fluids have lower thermal conductivity.
mass-flow rates. Thus, in the present work, some of the radiator
The present work is part of the design and parameters are changed to fit the present application,
construction of a Formula Student cart to Formula Student Car that has an engine CBR600rr
participate in the competitions of FSAE. Honda, which has 620cc and produces 75 kW BHP. It is
Interesting findings are presented and discussed. our objective to reject the heat produced to reach the
working temperature. A complete design and
KEYWORDS: mathematical calculation for the radiator needed is
I.C. Engine, Cooling system, Radiator, CFD introduced for the present application. The design
parameters for this kind of heat exchangers are
developed. Simulation tools, such as ANSYS-Fluent
software, are useful for the investigation and validation
III.1. Air
On the second part of the application, the air
system of heat transfer, which occurs largely by
convection. The high speed of the race car positively
affects the coefficient of heat transfer from the radiator
to the ambient air.
Fig.1 Present proposed (FSAE) car radiator. As there is a constant rate of heat transfer to be
removed to the ambient air, the required area (Ar) that
interfaces with the medium can be calculated as
III. MATHEMATICAL CALCULATIONS follows:
The present FSAE radiator is designed to Inlet air temperature: Tai = 20ᵒC
achieve the required heat transfer for the hot water Outlet air temperature: Tao = 85ᵒC
to obtain the working temperature. Convection heat transfer coefficient (h): 800 W/(m2.K)
III.1. Coolant q = h A (Tao - Tai) (5)
The amount of the heat that get out of FSAE Thus, 25,000 = 800 A (85-20)
car engine can be calculated as it is considered one- A = 0.48 m2
third of total power produced by the used engine. Based on this needed area, the length (L) of each of
As mentioned before, CBR 600rr is used, which the radiator tubes can be found from the following
can produce 75 kW BHP. This heat transfers to the relation:
coolant by conduction and convection. Then, heat A = (2 1.8 L2/0.75) + (2 0.169 L2/0.75)
is removed to the ambient air by radiation and A = 5.25 L2
convection methods. Thus, L = 35 cm
Thus, the resulted heat (q) from the present The number of tubes is assumed to be 40, with the
engine can be calculated as follows: width of the radiator (W) = 30 cm.
q = (1/3) engine BHP = (1/3) 75 = 25 kW (1)
After defining the fluid zone, Fig. 5, the Fig.7 Temperature distribution for fins
boundary conditions are defined, which include: (Red is the hottest and Blue is the coldest).