Methane Transcritical Behavior in the Cooling System of the HYPROB-BREAD LOX/LCH4 Demonstrator Rocket Engine

Abstract

The HYPROB Program, developed by the Italian Aerospace Research Centre, has the aim of increasing the Italian system design and manufacturing capabilities on liquid oxygen-hydrocarbon rocket engines; the most important activity is represented by the development and testing of a ground engine demonstrator of three tons thrust based on methane as propellant. The demonstrator baseline concept is featured by 18 injectors and is regeneratively cooled by using liquid methane. The cooling system has a counter-flow architecture and is made by 96 axial channels; methane enters the channels in the nozzle region in supercritical liquid condition, is heated by the combustion gases along the cooling jacket and then is injected into the combustion chamber as a supercritical gas. The goal of the present paper is to describe the activities supporting the cooling jacket design, aiming at identifying the optimal configuration of the cooling channels. 3-D CFD analyses have been performed on different cooling channel arrangements, in terms of channel height and rib width. Moreover, simulations described the thermo-fluid dynamic behavior of methane by means of NIST real gas modeling and they were necessary to give the proper input to the thermo-structural analyses in order to verify the most critical sections of the cooling jacket.

Thermal analyses supporting the development of a liquid rocket engine

“…If the "nominal" thermal load is considered for conservative purposes, the evaluated maximum values of temperature keep below the target of about 750 K. Thus, adopting the thermal coupling with thrust chamber, the wall temperature are expected to be further lower, as depicted by the axial profiles given in Figure 26. In fact, in the throat region a temperature value of about 610 K is detected while in the cylindrical part is about 660 K [26]. Moreover, pressure losses reduce of about 0.4 MPa.…”

Thermostructural Numerical Analysis of the Thrust Chamber of a Liquid Propellant Rocket Engine

“…The thermal and structural boundary conditions are shown in Figure 6 . Coolant bulk temperatures, combustion gases and their respective heat transfer coefficients, which varied along the axis of chamber, were carried out by computational fluid dynamics (CFD) analyses [ 35 , 36 ]. The heat transfer coefficients and bulk temperatures to be applied in the local model thermal analyses, ranged between the dashed lines in Figure 6 b.…”