Investigation of flow characteristics inside a dual bell nozzle with and without film cooling

Verma, Mayank; Arya, Nitish; De, Ashoke

doi:10.1016/j.ast.2020.105741

Cited by 18 publications

(6 citation statements)

References 40 publications

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“…For overcoming this problem investigated the result of using the film cooling and conclude the injection of the secondary flow into the nozzle at a different location. The result was carried out by various simulations and experiments [23]. Schneider et.al (2020) investigate the numerical study of a film-cooled dual bell extension on its operation mode transition behavior.…”

Section: …… (1)mentioning

confidence: 99%

“…The primary flow develops inside the nozzle. The injection of secondary flow occurs at 500K, Mach2, 1 mm of film cooling slot height [41]. The Influence of Nozzle Shape on Flux Distribution: The radiant flux has a parameter that depends on the nozzle shape.…”

Section: Thermal Characteristics Of Bell Nozzle In Supersonic Enginementioning

confidence: 99%

“…A diagram of the boundary layer growth in the nozzle may be seen in Figure 1. [41] FIGURE 5. Schematic interaction of hot gas and overexpanded coolant at the injection position for tangential injection, shocks, and expansion waves are not shown.…”

Section: Thermal Characteristics Of Bell Nozzle In Supersonic Enginementioning

confidence: 99%

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Review Study on Thermal Characteristics of Bell Nozzle used in Supersonic Engine

Guram¹,

Jadhav²,

Sawant³

et al. 2023

jame

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The nozzle is an important component of the rocket motor system, and a rocket’s overall performance is highly reliant on its aerodynamic design. The nozzle contour can be meticulously shaped to improve performance significantly. The design and shape of rocket nozzles have evolved over the last several decades as a result of extensive research. The nozzle design is composed of two components, an integrated throat, an entry and an exit cone, and a thermal protection system. The Bell Nozzle is designed to provide clearance space for placing the ITE and exit cone, with a cone inflection angle of 16 and a thermal protection system. This paper intends to review and summarize all such developments. Small-scale engine testing allows for the analysis of rocket nozzle materials, but the history of nozzle surface temperature and thermal stress may be adversely affected by side effects. The review focuses primarily on the nozzle shape which has the largest radiative flux past the neck, but the nozzle shape has the highest heat flux in the throat due to the mass-flow rate per unit area. The distribution of nozzle wall pressure is strongly influenced by the Mach number of the injected secondary flow, leading to undesirable side loads. Finally, future development possibilities are suggested.

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Section: …… (1)mentioning

confidence: 99%

Section: Thermal Characteristics Of Bell Nozzle In Supersonic Enginementioning

confidence: 99%

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Review Study on Thermal Characteristics of Bell Nozzle used in Supersonic Engine

Guram¹,

Jadhav²,

Sawant³

et al. 2023

jame

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“…A flat plate configuration implies that the study is conducted in the absence of a free stream pressure gradient. In internal flows, such as those that occur inside a rocket nozzle, the wall jet is expected to have a more prominent effect on the flow field [ 11 , 13 ]. Nozzle cooling systems are characterized by low injection angles, usually less than about 30° with respect to the surface.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Film Cooling Effectiveness in a Supersonic Nozzle

Somasekharan

Srikrishnan

Kumar

et al. 2023

Entropy

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Film cooling as applied to rocket nozzles is analyzed numerically with emphasis on the assessment of the effect of the mixing of coolant with the hot stream. Cooling performance, as characterized by cooling effectiveness, is studied for three different coolants in the three-dimensional, turbulent flow field of a supersonic convergent-divergent nozzle operating with a hot stream temperature of 2500 K over a range of blowing ratios. The coolant stream is injected tangentially into the mainstream using a diffuser-type injector. Parameters influencing the effectiveness, such as coolant injector configuration and mixing layer, are analyzed. Thermal and species mixing between the coolant and the mainstream are investigated with regard to their impact on cooling effectiveness. The results obtained provide insight into the film cooling performance of the gases and the heat transfer characteristics associated with these three gases. An injector taper angle of 30° results in the most effective cooling among the configurations considered (0°, 15°, 30° and 45°). Mixing of the coolant with the hot stream is examined based on the distributions of velocity, temperature and species. The higher values of cooling effectiveness for Helium are attributed to its thermophysical properties and the reduced rate of mixing with the hot stream. The results further indicate that through optimization of the blowing ratio and the coolant injector configuration, the film cooling effectiveness can be substantially improved.

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“…The altitude or the pressure at which the transition between the modes takes place must be planned and maintained exactly to be able to deliver the calculated payload. To ensure mode transition at fixed altitude, the timing of the transition can be controlled by varying the thrust chamber pressure [13] or the fuel mixture ratio [50] or a secondary mass flow near the deflection point can be used [51]. Schneider et al [41] suggest to use a combination of chamber mixture ratio as well as the cooling fluid mass flow rate to control the dual-bell mode transition.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the base flow of a generic space launcher with dual-bell nozzle

Scharnowski

Kähler

2020

CEAS Space J

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The typical afterbody flow of a space launcher is characterized by a strong interaction of the engine’s exhaust jet and the separated shear layer emerging from the main body. This interaction is further complicated by strong changes in the spatial and temporal behavior of the afterbody flow during the atmospheric ascent of a launcher. Theoretically, a dual-bell nozzle not only allows for a gain in payload compared to standard single-bell nozzles, but also it alters the wake flow topology due to the two nozzle modes. To predict the benefits as well as the additional risks, the afterbody flow of a generic space launcher model equipped with a cold-flow dual-bell nozzle is investigated in detail. The flow was analyzed for sub-, trans- and supersonic Mach numbers ranging from 0.3 to 2.9 for a variety of nozzle pressure ratios. Particle image velocimetry measurements and schlieren measurements with high repetition rate were performed to determine the dynamics of the separated shear layer, the nozzle jet and their interaction. It is shown that the reattachment length of the base flow decreases with increasing nozzle pressure ratio. Furthermore, the nozzle pressure ratio at which the dual-bell nozzle switches from sea-level mode to altitude mode is reduced by $$15\%$$ 15 % with high subsonic outer flow and by as much as $$65\%$$ 65 % for an outer flow at a Mach number of 1.6. Even for a constant nozzle pressure ratio, the nozzle flow topology depends on the Mach number of the outer flow.

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Investigation of flow characteristics inside a dual bell nozzle with and without film cooling

Cited by 18 publications

References 40 publications

Review Study on Thermal Characteristics of Bell Nozzle used in Supersonic Engine

Review Study on Thermal Characteristics of Bell Nozzle used in Supersonic Engine

Enhancement of Film Cooling Effectiveness in a Supersonic Nozzle

Investigation of the base flow of a generic space launcher with dual-bell nozzle

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