Theoretical and Experimental Heat Transfer in Solid Propellant Rocket Engine

by Izabel Cecilia Ferreira de Souza Vicentin, Carlos Henrique Marchi, Antonio Carlos Foltran, Diego Moro, Nicholas Dicati Pereira da Silva, Marcos Carvalho Campos, Luciano Kiyoshi Araki, J. Aerosp. Technol. Manag., São José dos Campos, v11, e3819, 2019 https://doi.org/10.5028/jatm.v11.1066 ORIGINAL PAPER 1.Universidade Federal do Paraná – Setor de Ciências Exatas – Engenharia Mecânica – Curitiba/PR – Brazil. 2.Universidade Positivo – Engenharia Mecânica – Curitiba/PR – Brazil. *Correspondence author: izabeldesouza@gmail.com Received: Feb. 6, 2018 | Accepted: Oct. 30, 2018 Section Editor: T John Tharakan ABSTRACT: Accurate determination of heat flux is an important task not only in the designing aspect, but also in the performance analysis of rocket engines. In this purpose, this work deals with the heat flux determination in a combustion chamber through the inverse method. In this approach, the transient heat flux is determined from the experimental temperature data measured at the outer sidewall of the rocket engine. In this work the physical phenomenon was modeled by the transient one-dimensional heat equation in cylindrical coordinates and the material properties of the chamber were considered constant. Furthermore, the model is solved using the inverse heat conduction problem with least squares modified by the addition of Tikhonov regularization term of zero-order. Moreover, the sensitivity coefficients were obtained by Duhamel’s theorem. Through the regularization parameter, it was able to generate acceptable results even when using data with considerable experimental errors. KEYWORDS: Combustion chambers, Heat flux, Heat conduction, Ill-posed problems. INTRODUCTION In a thrust chamber (nozzle and combustion chamber), the amount of energy transferred as heat to the chamber walls is between 0.5% and 5% of the total generated energy (Sutton 1992). Nevertheless, this amount could be enough to cause structural failure. Thus, to prevent the chamber and nozzle walls from failing, it is necessary to predict the heat flux accurately. Furthermore, accurate determination of heat flux is also important in the calculation of rocket engine performance and for the cooling system design. Convective and radiative heat transfer must be determined for characterization of total heat flux. The convective heat transfer coefficient typically depends on many fluid physical properties. The computation of the radiation heat transfer must be accounted by the surfaces emissivity and the absorption and scattering coefficients of the fluid mixture. However, information about these parameters is not always easily found. Considering the propellant applied in this work (potassium nitrate with sucrose, KNSu), the combustion products that affects radiation heat transfer are predominantly Theoretical and Experimental Heat Transfer in Solid Propellant Rocket Engine Izabel Cecilia Ferreira de Souza Vicentin1,*, Carlos Henrique Marchi1, Antonio Carlos Foltran1, Diego Moro1,2, Nicholas Dicati Pereira da Silva1, Marcos Carvalho Campos1, Luciano Kiyoshi Araki1, Alysson Nunes Diógenes
Published 2019-08-01