PENGARUH PENAMBAHAN ATAP SEKUNDER KABIN MOBIL (SECONDARY CABIN ROOF) TERHADAP GAYA AERODINAMIS DAN 2) PERILAKU ARAH PADA MOBIL SEDAN
Abstract: This paper describes
aerodynamic tests (wind tunnel test) for a model of secondary cabin roof (SCR)
applied in BMW M3 E92 Coupe. SCR is a vehicle accessory installed on vehicle
roof useful to block heats from sun while the car parking. The test were
conducted at UPT-Laboratorium Aero Gas Dinamika dan Getaran (LAGG)-BPPT,
PUSPITEK, Serpong, to determine lift and drag coefficient (cl and cd) of
vehicle. This model with scale of 1:4.5 was tested with rigid body made by
wood. The SCR model has been made from aluminium and has two kinds of type,
which are A and B. The model test was carried out with the following
parameters: wind speed of 15, 20 m/s, then 1,5 cm and 2,5 cm for height of SCR
from roof . Before the test start, the first things that must be done is
preparation the tools for test, next step is calibration of external balance in
wind tunnel to obtain matrix of calibration. The inverse of this matrix named
matrix of test will be used as a multiply factor to voltage measurement from
result test of external balance while test start. Output from this multiply is
aerodynamic forces experienced by model test. Installing SCR made some change
to aerodynamic experienced by vehicle. From data of test, installing SCR type B
with height 1,5 cm rom roof, the smallest cl can be obtained for each variation
of velocity are 0,3 for 15 m/s and 0,29 for 20 m/s. Meanwhile, installing SCR type A with height 2,5 cm from
roof, the smallest cd be obtained for each variation of velocity are 0,368 for
15 m/s and 0,355 for 20 m/s. This results are valid if only the flow regime of
two corresponding fluid are same and with the same model too.
Penulis: Ahmad Suudi, A.Yudi
Eka Risano, Andy Abdel Hakim
Kode Jurnal: jptmesindd130509
