Experimental And Numerical Research On Heat Transfer Performance Of Oscillating Heat Pipe Grinding Wheel

In grinding of hard-to-machining materials such as titanium alloys and super alloys,a massive grinding heat is gathered in the processing zone.It easily causes a grinding burn to workpiece,which has become one of the main problems restricting the improvement of grinding efficiency and quality.The existing cooling system of machine tools is mostly based on the coolant,but due to the closeness of the grinding zone,it's more and more difficult for the coolant to be injected to the contact zone with the increasing grinding parameters.Therefore,in order to effectively solve the problem of grinding burn,this paper applied the oscillating heat pipe(OHP)to the grinding wheel and put forward the concept of the OHP grinding wheel to enhance the heat exchange capacity in the grinding zone.Based on the concept,some heat transfer experiments were carried out.And the heat transfer performance of oscillating heat pipe was analyzed under axial rotation.The heat transfer capacity needed was simulated for the condensation section of the OHP grinding wheel under axial rotation,which confirm the structure form and high pressure cooling air conditions to achieve the heat transfer capacity.The heat conduction enhancement effect of the OHP grinding wheel was vertifed through the simulation of the grinding temperature field of the grinding wheel and workpiece.(1)The heat transfer performance experiment platform was established for the rotation oscillating heat pipe to investigate the heat transfer capacity.And the heat transfer performance experiment of single loop oscillating heat pipe was carried out under the axial rotation condition.The influence of different rotating speeds,working fluids and heat flux on its heat transfer capability was analyzed.According to the experiment result the working fluid with the best heat transfer capability was obtained.And based on the experimental data,an artificial neural network model was established to predict the heat transfer performance of the oscillating heat pipe.(2)In order to allow the oscillating heat pipe work effectively,the heat exchange capacity of the condensation section should ensure that the heat can be released to the environment in time.In this paper,the simulation of forced convection heat transfer performance of condensation section was carried out.The high pressure cold air jet and fins were used to enhance the heat transfer capacity of the grinding wheel condensation section.And the cooling effects of fins with different structures were compared.Based on the simulation results,the fin structure were selected,and further simulation results of the heat transfer performance under different rotating speeds and cold air conditions were discussed.(3)On the basis of the results of oscillating heat pipe heat transfer experiment and condensation section simulation,The concept of OHP grinding wheel was raised preliminarily.The grinding temperature simulation of oscillating heat pipe wheel was carried out.The heat flux in the grinding contact zone was determined according to the grinding parameters.The grinding temperature field of the OHP grinding wheel with the number of oscillating heat pipe of 0,2,4 and 6 was compared.The temperature and its distribution of the grinding wheel and the workpiece were analyzed.And it was vertified that the oscillating heat pipe had the capacity of enhancing the heat exchange in the grinding contact zone.