A New Erosive Burning Model of Solid Propellant Based on Heat Transfer Equilibrium at Propellant Surface

Abstract

Erosive burning refers to the augmentation of propellant burning rate appears when the velocity of combustion gas flowing parallel to the propellant surface is relatively high. Erosive burning can influence the total burning rate of propellant and performance of solid rocket motors dramatically. There have been many different models to evaluate erosive burning rate for now. Yet, due to the complication processes involving in propellant and solid rocket motor combustion, unknown constants often exist in these models. To use these models, trial-and-error procedure must be implemented to determine the unknown constants firstly. This makes many models difficult to estimate erosive burning before plenty of experiments. In this paper, a new erosive burning rate model is proposed based on the assumption that the erosive burning rate is proportional to the heat flux at the propellant surface. With entrance effect, roughness, and transpiration considered, convective heat transfer coefficient correlation proposed in recent years is used to compute the heat flux. This allows the release of unknown constants, making the model universal and easy to implement. The computational data of the model are compared with different experimental and computational data from different models. Results show that good accuracy (10%) with experiments can be achieved by this model. It is concluded that the present model could be used universally for erosive burning rate evaluation of propellant and performance prediction of solid rocket motor as well.

Extended Application and Experimental Verification of a New Erosive Burning Model Coupled Heat Transfer between Gas and Grain Based on a Star-Grain Solid Rocket Motor

“…In this paper, two different erosive burning models are used for comparison purposes. The first is the Ma model [17]. In this model, the total burning rate comprises the following two components: the normal burning rate and the erosive burning rate.…”

“…The code used in this paper evolved from the code developed by the authors in Ref. [17], to accommodate the star grain in the SRM studied in this paper. During the computation, the SRM For the star grain with an arc at the star tip, the burning process of the grain can be divided into four stages.…”

“…Greatrix [16] compared the results from Mukunda's model to some classical studies, and indicated that the roughness of the propellant surface should also be considered. Ma and coauthors [17] proposed another erosive burning model. By evaluating the heat flux using the heat transfer model of Gnielinski [18], the model of Ma released all the unknown constants, making it another universal model to estimate the erosive burning rate.…”

“…In this paper, the code the authors developed in Ref. [17] is extended to a star-grain SRM, with a large aspect ratio, to obtain the internal ballistics results. The Ma model and Mukunda model are used for erosive burning evaluation.…”

Using Surface Grooves on Propellant Grain to Control the Erosive Burning in Solid Rocket Motors

“…In addition, the most recent investigations on the erosive burning phenomenon have demonstrated that the experimental calibration of the models is still necessary [12], the erosive burning rate is proportional to the heat flux on the propellant surface [13], and the quasi-one-dimensional simulations of the internal ballistics of the solid rocket motors using the two-dimensional grains have acceptable accuracy for performance prediction [14]. It should be emphasized that erosive burning is not always harmful, but can sometimes be used to improve the performance especially for the solid rocket motors with progressive burning propellant grains [15].…”