Numerical Investigation on the Thermal Behaviour of a LOx/LCH4 Demonstrator Cooling System

Abstract

Reliability of liquid rocket engines is strictly connected with the successful operation of cooling jackets, able to sustain the impressive operative conditions in terms of huge thermal and mechanical loads, generated in thrust chambers. Cryogenic fuels, like methane or hydrogen, are often used as coolants and they may behave as transcritical fluids flowing in the jackets: after injection in a liquid state, a phase pseudo-change occurs along the chamber because of the heat released by combustion gases and coolants exiting as a vapour. Thus, in the development of such subsystems, important issues are focused on numerical methodologies adopted to simulate the fluid thermal behaviour inside the jackets, design procedures as well as manufacturing and technological process topics. The present paper includes the numerical thermal analyses regarding the cooling jacket belonging to the liquid oxygen/liquid methane demonstrator, realized in the framework of the HYPROB (HYdrocarbon PROpulsion test Bench) program. Numerical results considering the nominal operating conditions of cooling jackets in the methane-fuelled mode and the water-fed one are included in the case of the application of electrodeposition process for manufacturing. A comparison with a similar cooling jacket, realized through the conventional brazing process, is addressed to underline the benefits of the application of electrodeposition technology.

Transcritical Behavior of Methane in the Cooling Jacket of a Liquid-Oxygen/Liquid-Methane Rocket-Engine Demonstrator

“…The test campaign was successfully performed, considering the following test parameters: Results from the numerical rebuilding activity in terms of fluid temperature, pressure drops, and channel wall-temperature values were in good agreement with the experimental data, as also reported in [38]. In fact, the maximum discrepancies in terms of fluid-temperature differences between inlet and outlet sections and pressure drops are equal to about 1.3% and 4.0%, respectively, while differences in terms of the channel's bottom surface is maximum 1.0%.…”

“…Moreover, a validated numerical procedure has been set up in view of being adopted to run the thermal simulations on the HYPROB final Demonstrator first unit (DEMO-0A), supporting the detailed design. Further information on the program and on the realized breadboards are available in [14,16,38]. It is worth highlighting that the application of the classical semiempirical correlations, adopted to calculate the evaluation of heat-transfer coefficients, does not produce reliable results in the deteriorated mode, and in addition, high values of relative roughness also represent a challenging condition from the numerical-modeling point of view.…”

“…Moreover, a validated numerical procedure has been set up in view of being adopted to run the thermal simulations on the HYPROB final Demonstrator first unit (DEMO-0A), supporting the detailed design. Further information on the program and on the realized breadboards are available in [14,16,38].…”

Thermal Behaviour of the Cooling Jacket Belonging to a Liquid Oxygen/Liquid Methane Rocket Engine Demonstrator in the Operation Box

“…The computational domain also included both solid parts, which consisted of the thrust chamber liner, which was made of CuCrZr copper alloy, while the electrodeposited layer on the rib surface was made from pure copper and, for the close-out, pure nickel was used (see Figure 6). All the thermo-physical properties were considered as a function of temperature and evaluated by means of specific activities associated with material thermomechanical characterization via a dedicated characterization activity [51], in line with data cited in the literature [52]. Because a symmetrical model has been considered, only half the channel has been simulated in order to limit the computational effort.…”

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

“…Furthermore, several efforts have been made to study the thermal efficiency of the cooling system of regeneratively cooled thrust chambers by means of thermal and fluid-dynamic numerical investigations [ 9 , 10 ].…”