Research On Icing Condition Detection Method And Simulation Based On Heat Transfer

Icing is a serious threat to aircraft safety.Aircraft icing detection technology is an important component of icing protection system.The icing condition detection technology directly detects the meteorological conditions to judge the potential icing hazards,which is the new direction of the icing detection field.Compared with the frozen icing detection method,it has the characteristics of high accuracy and good early warning,which is beneficial to the aircraft airworthiness certification process and of great significance to improve the safety protection level of aircraft icing.First,the analysis of icing detection technology is carried out,and a method of detecting icing conditions based on heat transfer principle is studied in this thesis,including the design of probe diversion configuration,the arrangement of probe and the realization of measuring circuit.Then the Lagrange method is used to establish the water droplet equation of motion,and the trajectory of the water droplet is calculated.Based on the heat transfer principle of the probe in gas-liquid two-phase flow,the thermodynamic model of cylindrical flow around is established.Then,the CFD numerical simulation method is used to build the basic platform of numerical calculation.The UDF is written and chained into the numerical calculation model.The numerical calculation of the flow field is carried out and the calculation results are analyzed to verify the validity of the numerical calculation platform.Then,based on the basic platform of numerical calculation,the effects of liquid water content,water droplet size,flight speed and atmospheric temperature on the measurement model were studied by simulating the movement,impact and evaporation phase transition of droplet.Finally,the results of numerical calculation are analyzed,and the settlement of the icing weather condition is obtained by the compensation method.The results of numerical calculation show that the dual probe detector configuration achieves the compensation effect of air convective heat transfer under the constant temperature working mode,and the liquid water content can still be measured by the electric power of the probe resistance under the specific influence of flight speed and atmospheric temperature.Furthermore,it is possible to solve the icing meteorological conditions based on the ice-confinement envelope.