Week 4 - CHT Analysis on Exhaust port
CONJUGATE HEAT TRANSFER
introduction
this type of heat transfer corresponds to a combination of the heat transfer in solids and heat transfer in fluids .heat transfer in solid is called conduction and heat transfer in a fluid is called convection.
conduction occurs due to the Direct molecular collision. the faster kinetic energy collides with the low-speed kinetic energy and heat transfer occurs
convection process is not happed alone, it is combined with conduction or radiation
so, the conjugate heat transfer occurred mostly in the cooling process like Heat sink, battery cooling, airflow over the sloid object for cooling.
whenever the solid and fluid interface appears, this type of CHT analysis can be done to find the optimum result by using ANsys, it allows the simulation of the heat transfer between solid and fluid domains by exchanging the thermal energy at the interface between then
#geometry
#meshing
infliction layer calculation
velocity=5 m/s
lenght is =1.66m(dia)
y+ value is =100
first layer thickness got is =0.0056 m
total Nodes- 124156
elements- 433645
#boundary condition
inlet velocity is 5m/s
temperature is 700k
outer wall heat convention is 20 w/m-2k
#results
residuals
y+ vs turbulence
2)solver k-epsilon used so for this yplus value should be 30-300, when we observed graph most value come under more the 30, it shows that model calculation and model used for solver are right
Temprature wall convection
teat transfer coefficient and velocity
wall heat transfer coefficient
velocity graph
verification of results
the results can be verified by doing experiments physically or by performing grid dependency tests.
in convection, we can verify by Nusselt number, Prandtl number, Reynolds numbers
Nusselt numbers Nu=hl/k
factor effects simulation are
Share topology
inflation layer
number of elements
conclusion
from all the above graphs, we can say that where the temperature is maximum there velocity, heat transfer coefficient are also maximum at that point we get minimum pressure.