• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.5
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• pp.10-18
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• 2019

In this study, flow characteristics and the starting pressure of a center body diffuser (CBD) were analyzed at various center body (CB) positions and cone angles. According to the CB position, the location of oblique shock moved to the front from behind the CB cone with an increase in the flow momentum. Additionally, when a strong oblique shock occurred, the direction of supersonic flow was affected and induced to diffuser wall. As a function of different cone angles for the oblique shock, the starting pressure of the CBD was significantly affected.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.2
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• pp.93-102
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• 2016

An experimental study has been conducted to verify the startup characteristic of a Center Body Diffuser (CBD) for simulating a low pressure environment when at high altitudes. Vacuum chamber pressure and startup characteristics of the CBD were investigated according to various geometries of the center body structure by a cold gas flow test. The test results show that the startup pressure is lowest when the center body contraction angle is approximately $15^{\circ}$. The startup characteristic of the CBDs significantly improves when the diffuser inlet length ($L_d/D_d$) is decreasing and the divergence length ($L_s$) is increasing. Additionally, it is possible to simulate various high altitude, low pressure conditions for various rocket engines that have different nozzle expansion ratios by adjusting the center body's position inside the diffuser.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1148-1152
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• 2017

To simulate a high altitude for rocket at sea level, the test facility should provide a sufficiently low pressure environment. Center Body Diffuser(CBD) is those applied for high altitude simulation test facility. To elucidate the flow characteristics of center body diffuser with various the center body location, numerical analyses using ANSYS FLUENT were performed. The result of this study is deemed to be valuable as a data base for the operation of the Center Body Diffuser.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.34-39
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• 2014

A study is analyzed on the design factor of center-body diffuser and performed on conceptual design of center-body diffuser with computational fluid dynamic. The flow field of center-body diffuser is calculated using axisymmetric two-dimensional Navier-Stokes equation with $k-{\epsilon}$ turbulencemodel. The center-body diffuser is compared with second throat exhaust diffuser in terms of starting pressure, the degree of vacuum pressure and the design factors. The counter flow jet on cone-tip of the center-body is applied for thermal protection system in the center-body diffuser.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.487-491
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• 2009

A study is analyzed on the design factor of Center-body diffuser and performed on conceptual design of Center-body diffuser with Computational Fluid Dynamic. The flow field of Center-body diffuser is calculated using Axisymmetric two-dimensional Navier-Stokes equation with $k-{\omega}$ turbulence model. The center-body diffuser is compared with second throat exhaust diffuser in terms of starting pressure, the degree of vacuum pressure, the design factor.