Combined RANS/DNS analysis of conjugate heat transfer in rocket cooling channels

Anno
2018
Proponente Francesco Nasuti - Professore Ordinario
Sottosettore ERC del proponente del progetto
Componenti gruppo di ricerca
Abstract

The advancement of technologies for the realization of rocket thrust chambers allows the selection of new design and materials as well as new liquid propellants as coolants. One of the keys for the success of a new technology is the capability to realize safe and efficient designs of the cooling systems. To this goal, an important support is provided by numerical simulations, which must be reliable and efficient. The present research aims at studying the role of the material selection on the coolant behaviour, especially in presence of high heat loads, as those occurring in liquid rocket engines. The study is carried out with a conjugate heat transfer numerical approach, which has been already validated for specific test cases. It is based on in-house solvers for the solution of both steady Reynolds Averaged Navier Stokes (RANS) equations in the channel and heat conduction equation in the material. An additional analysis with Direct Numerical Simulations (DNS) will strengthen the value of the RANS solution and further validate the averaged approach. The in-house DNS code solves for the three-dimensional, unsteady Navier-Stokes equations down to the dissipative scale. The solver relies on the immersed-boundary method to handle complex geometries, and it is capable of handling conjugate heat transfer problems through local suppression of convective terms and change of the heat conduction coefficient within solid zones. The reference geometry for the study is a straight channel with rectangular cross section. After a comparison of results on thermally developed water test cases, simulations will be carried out including two metallic materials one featuring high thermal conductivity and one low thermal conductivity. The different thermal conductivity affects the distribution along the channel perimeter of the heat flux entering the coolant flow and may enhance or discourage thermal stratification and the possible occurrence of heat transfer deterioration.

ERC
PE8_1
Keywords:
PROPULSIONE AEROSPAZIALE, INGEGNERIA AEROSPAZIALE, SCAMBIO TERMICO E DI MASSA, TURBOLENZA, MECCANICA DEI FLUIDI

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