Based On Dot Matrix Heating The Study Of Temperature Gradient Field For Metal Wing Structure

When the high-speed vehicle is in normal flight, the temperature gradient field that takes place in the aircraft skin is nonuniform by the complicated heating effect. In order to ensure the safety of the airplane, it needs to do some heating tests on it. The present heating methods on airplane are radiant heating method and wind tunnel heat flow heating method. These affect the external environment which make the close operation is inconvenient while we are doing testing experiment and have high demanding on the equipments. Therefore, based on small size induction heating coil as heating load, the paper layouts heating coil with dot matrix arrangement and propose three temperature control methods of dot matrix heating system.And the temperature field of heating by the coil is got through the finite element anslysis simulation. The work is as follows:1. Based on Maxwell Equations research on the induction heating coil, using the electromagnetic theory the induced field of induction coil is calculated. The power of the induction coil is counted with a plate as the experimental sample.2. Presentation of the dot matrix heating method is carried out. By means of heat conduction theory, the feasibility of the temperature field with the dot matrix heating is approved. Based on the finite element theory, the characteristics of heat transfer and boundary conditions for dot matrix heating are analysised. Through the parts of spatial domain and time domain, the method for calculating the transient heat transfer temperature field of dot matrix heating coil system is analysed. The design and temperature control method for the dot matrix heating scheme are introduced. According to the heat conduction theory, dot matrix gradient principle and highest temperature principle which apply to the process of dot matrix load control are proposed.3. Based on metal wing structure design the dot matrix heating scheme, finite element model is built, continuous control method, discontinuous control method and on-off control method are put forward. According to dot matrix gradient principle and highest temperature principle program for cycle controlling load is made in APDL software. Using thermal transient analysis the temperature fields with the three control methods are got and the difference between the heat temperature and the target temperature is in a permitted range. Through analysing the change of the dot matrix loads, some regularity is found in heating load controlling and the regularity meet the principle of the paper.4. Power control method for induction heating coil is discussed, for example in on-off control method, control circuit of induction coil is designed with IGBT as switch which can control on and off to adjust the power.