Numerical analysis of high aspect ratio cooling passage flow and heat transfer

Abstract

A program for three-dimensional flow and heat transfer analysis in a rocket engine cooling channel of high aspect ratio is described. The program, which is based on the parabolized Navier-Stokes equations, was validated by comparing flow and heat transfer calculations with measurement data as found in the literature. Calculations were performed for cooling channel flow of an actual 100 bar engine. Calculated hulk temperature rise and pressure drop data agree well with data obtained from test results. A parameter study shows the effects of turbulence intensity, wall surface roughness, heat transfer boundary caridition, and near-wall flow model.It is shown that the program can be successfully used for three-dimensional analysis of flow and heat transfer in rocket engine cooling channels. It is sufficiently CPU-time efficient and easy to handle to be employed in support of the design process of present and future rocket engine combustion chdmbers. NomenclatureA = cross-section area AR = aspect ratio = WW c = specific heat at constant pressure Dh= hydraulic diameter h =channel's height (radial direction) m =mass flow rate Nu = Nusselt number O/F= mixture ratio p = static pressure q, = wall heat flux Rc =channel's mean radius of curvature Re =Reynolds number based on hydraulic diameter T = static temperature Tbun = bulk temperature Tu =turbulence's intensity u,v,w = velocity components in cross-stream and streamwise uy = shear velocity w = channel's width (spanwise direction) X =coordinate along the combustion's chamber axis P directions, respectively * DASA Spa-Communications and Propulsion Systems Division. SOW MUnchm 80 e

Cryogenic liquid rocket engine technology developments within the German National Technology Programme

“…The 3-D CFD program VADUCT ('variable area ducts') was developed by Dasa to simulate the three dimensional flow and heat transfer in typical coolant channel geometries [8], [9]. Model experiments with air in large scale coolant channels (scale 25:1) heated on the hot gas side performed at the Technical University Dresden [6] showed good agreement between calculated and measured flow behaviour.…”

Evolution of cooling-channel properties for varying aspect ratio

“…The validity of the selected 3D CFD solver has been, in turn, proved in past studies by successful comparisons against experimental data relevant to cooling channel §ow and heat transfer [10,11]. The channel geometry has been selected as equal to that of the European Vulcain engine in the throat region [5]. The channel cross section has an aspect ratio of λ = 8.46 and the following dimensions (see Fig.…”

“…Moreover, a straight portion of length L = 40 cm is considered and the channel surface is considered smooth. The mass §ow rate and the inlet conditions of the hydrogen §ow and the hot-gas-side wall temperature are selected accord- [5,14]: ' m = 92.8 g/s, T in = 75 K, p in = 130 bar, and T w,hg = 800 K. Hydrogen thermodynamic behavior is described by means of the modi¦ed Benedict Webb Rubin equation of state [15] for both solvers. The 3D CFD solution has been veri¦ed by a grid convergence analysis that has been presented in [16].…”

“…1). For this reason, HARCC have been studied by NASA since many years [1 4] and introduced in engines like the European Vulcain [5]. In fact, reducing wall temperature allows increasing engine life and cost of fabrication, as resulted during development and production of Space Shuttle main engine.…”

Visualization of secondary flow development in high aspect ratio channels with curvature

“…In such a case, the benefits of the high aspect ratio geometry would be reduced. Other numerical studies, such as Yagley et al [6] and Lebail and Popp [7], have investigated high aspect ratio rocket engine coolant channels, but these efforts have been hampered by a lack of sufficient validating data.…”