Continuing Cooling Performance Investigation of a Rear Mounted Cooling Package for Heavy Vehicles Chalmers Univ. of Technology

Format:

Conference/Event

Author/Creator:

Larsson, Larsson, author.

Contributor:

Dahl, Erik

Löfdahl, L. (Lennart)

Wiklund, Torbjörn

Conference Name:

Commercial Vehicle Engineering Congress (2011-09-13 : Chicago, Illinois, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2011

Summary:

This investigation is a continuing analysis of the coolingperformance and aerodynamic properties of a rear-mounted coolingmodule on a semi-generic commercial vehicle, which was carried outby Larsson, Löfdahl and Wiklund. In the previous study two designsof the cooling package installation were positioned behind the rearwheelhouse and the results were compared to a front-mounted coolingmodule. The investigation was mainly focused on a critical coolingsituation occurring at lower vehicle speeds for a localdistribution vehicle. The conclusion from the study was that thecooling performance for one of the rear-mounted installation wasfavorable compared to the front-mounted cooling package. This wasmainly due to the low vehicle speed, the high fan speed and tofewer obstacles around the cooling module resulting in a lowersystem restriction within the installation.The main purpose with the present investigation was to determinethe power needed to overcome the aerodynamic drag together with thepower needed by the fan to obtain a specific cooling performance ata higher vehicle speed. One front- and three rear-mounted coolingpackage installations were included in the analysis. The vehiclegeometry was modified to be able to implement the changes for therear cooling module installations; the design of the air inlet, airoutlet and the duct in front of and after the cooling package werechanged for the rear-mounted cooling package installations toimprove the airflow and as a result the cooling performance. Theinvestigation was performed by the use of Computational FluidDynamics.It was found that the total power required due to aerodynamicdrag and fan operation to obtain a specific cooling performance wasreduced for two of the rear-mounted compared to the front-mountedcooling module. Even though the fan for these installationsrequired more power, the total power needed by the vehicle wasdecreased due to a lower aerodynamic resistance. The total powerdemand was reduced by 1.9 kW for one of the rear-mountedinstallations compared to the front-mounted cooling package.Furthermore it was established that the design of the air inlet fora rear-mounted cooling package was important to obtain a low totalpower demand, a high mass airflow through the cooling module and toobtain a uniform flow over the heat exchangers. For criticaldriving situations due to cooling performance, occurring at lowervehicle speeds, the rear-mounted cooling packages also gave afavorable cooling performance compared to the front-mounted coolingmodule installation. This was mainly due to the lower systemresistance and higher static fan efficiency for theseinstallations. To increase the cooling performance and decrease thepower requirement even more the air inlet, the fan choice and theduct geometry could be further developed

Notes:

Vendor supplied data

Publisher Number:

2011-01-2285

Access Restriction:

Restricted for use by site license