磁增强纳米流体荷电雾化机理及雾滴可控输运微量润滑磨削新方法

According to the principles of electrostatics and the charged mechanism of interelectrode corona, this program proposed a new MQL grinding method with controllable motion trail of charged efflux, droplet size and distribution as well as the contact status between droplets and workpiece interface. In this new method, the lubricant droplets will be charged atomized by the coupling effect of magnetic field and high-voltage electrostatic field after the nanofluids are sprayed from the nozzle, and then sprayed into the grinding zone as efflux. Based on the negative corona discharge of droplets under the coupling effect of multi-fields and its charged physical mechanism, effect law of electric field intensity, discharge current and corona onset voltage on effective charge of droplets was studied. The mathematical model concerning corona charging capacity of droplets in the magnetic reinforced high-voltage electrostatic field and the theoretical critical field intensity of droplet breakage was established. Kinematics and kinetic equations of charged droplets were deduced. Cooling and lubrication mechanism of the contact form between droplet and workpiece interface was disclosed in considering of the grinding wheel/workpiece constraint wedge-shaped space, disturbance of grinding wheel’s air barrier layer, and relative movement speed of grinding wheel/workpiece height. Thermodynamic effect and antifriction mechanism of heat transfer enhancement of nanofluid charged droplets on abrasive particle/workpiece interface and abrasive particle/cutting interface were discussed. On this basis, active control strategy of droplet size, spectral distribution, motion trail and contact form with interfaces based on coordinated parameter adjustment of electromagnetic field was explored.

项目依据静电学原理和极间电晕荷电机理，提出：将纳米流体从喷嘴喷出后，通过磁场和高压静电场耦合作用，使润滑剂液滴荷电雾化以射流形式喷入磨削区，实现带电射流的运动轨迹、雾滴粒径及其分布、雾滴与工件界面接触状态可控输运的微量润滑磨削新工艺。项目基于液滴在多场耦合作用下负电晕放电和液滴荷电的物理机制，研究电场强度、放电电流、起晕电压等对雾滴有效荷电的影响规律；建立液滴在磁增强高压静电场中电晕荷电量和液滴破碎理论临界场强的数学模型，推演出带电液滴的运动学及动力学方程。针对砂轮/工件约束楔形空间、砂轮气障层扰动、砂轮/工件高相对运动速度等条件，揭示雾滴与工件界面的接触形态对冷却和润滑作用机制；研究纳米流体荷电雾滴在磨粒/工件界面、磨粒/切屑界面强化换热的热力学作用规律及减摩抗磨的摩擦学机理；以此为基础，探索基于电磁场参数协同调节的雾滴粒径及其雾滴谱分布、雾滴运动轨迹、雾滴和界面接触形态的主动控制策略。

依据静电学和极间电晕荷电原理提出将纳米流体从喷嘴喷出后，通过磁场和高压静电场耦合作用，使润滑剂液滴荷电雾化以射流形式喷入磨削区，实现带电射流的运动轨迹、雾滴粒径及分布、雾滴与工件界面接触状态可控输运的微量润滑磨削新工艺。基于液滴在多场耦合作用下放电和荷电机制，研究场强、起晕电压等对雾滴有效荷电的影响规律；建立液滴在磁增强高压静电场中电晕荷电量和液滴破碎临界场强的数学模型，推演出带电液滴的运动学及动力学方程。针对砂轮/工件楔形空间、气障层扰动等条件，揭示雾滴与工件界面的接触形态对冷却润滑作用机制；研究纳米流体荷电雾滴在磨粒/工件、磨粒/切屑界面的热力学作用规律及摩擦学机理；提出基于电磁场参数协同调节的雾滴粒径及分布、雾滴运动轨迹、雾滴和界面接触形态的主动控制策略。建立了纳米流体运动学及动力学模型、楔形接触区浇注式和微量润滑两种供液条件下的动压力理论模型与数值仿真、研究喷射参数对有效流量率的影响规律。揭示了纳米粒子射流强化换热机理及磨削介质对磨削区的热力学作用机理，建立了纳米粒子射流微量润滑强化换热及能量比率数学模型；揭示了纳米粒子理化特性、携带流体特性、液固界面特性等对强化换热的影响规律。研究了纳米粒子的浸润特性及其剪切油膜形成与流体动压力的作用规律，研究了纳米粒子射流不同理化特性对砂轮/工件界面摩擦学特性及切屑形成、砂轮磨损和工件表面质量的作用机理与影响规律。搭建了纳米流体静电雾化微量润滑磨削平台，进行不同润滑方式下磨削加工性能实验评价与量化表征。共发表论文45篇，其中SCI-JCR(1-2)区 37篇，机械工程学报3篇，ESI热点论文1篇、高被引论文6篇。出版著作4部，其中英文著作2部；授权中国发明专利23项，国外发明专利4项， PCT专利20项，软件著作权15件。获得中国专利优秀奖，山东省技术发明一等奖，教育部技术发明二等奖、山东省专利一等奖，中国产学研合作创新成果一等奖，中国循环经济协会专利金奖等科研奖励19项。