Study Of Underhood Thermal Management Of A Forklift Truck

With the development of the automotive industry, the increasing requirements of the automotive power, economy and reliability made the structure layout of the underhood more and more crowd which has brought the great pressure and challenge to the compartment cooling. With the development of computing hydrodynamics and computer technology, the numerical simulation technology can be better simulate the heat flow field in the underhood, effectively shorten the development cycle and reduce development costs, eventually forming for automotive engine compartment thermal management research methods.In this paper a domestic forklift as the research background, firstly, through the establishment of the cooling fan of the engine bench test simulation model and the CFD numerical calculation model of the cold and hot side coupling heat dissipation of the radiator, verify the radiating components performance parameters requirements; And then a simplified three-dimensional geometric model of forklift underhood was setup, and a high quality computing grid model are obtained based on Hypermesh and STAR-CCM +. At engine power rating conditions, the flow field and temperature field distribution were figured out through analysis the vehicle engine cabin heat dissipation characteristics, the causes of heat reflux, eddy current, stagnation and local higher temperature were found out. Aiming at the problem of poor heat dissipation characteristics of the engine cabin, four improvement schemes were proposed, based on considerations of R&D period and cost, determine to choose strong implemental and cost-effective schemes: to seal the gap between radiator and fan shroud, to add choke plate and guide plates, to increase the air outlet slit. Then the modified vehicle cabin heat dissipation characteristics were analyzed under the same conditions.The results show that: compared to the prototype vehicle, the modified vehicle cabin internal heat reflux, eddy current and stagnation phenomenon were effectively blocked and improved, air flows more smoothly and regular; The inlet air temperature of radiator and fan has an apparent decrease; Radiator windward mass flow and heat transfer power have varying degrees of upgraded, the whole heat dissipation characteristic of the underhood has been improved.