Effects of Gas Generator Burn Rate Variability on Variable Flow Ducted Rocket Design and Performance

Author(s):  
Daniel MacInnis
Author(s):  
Hisahiro Nakayama ◽  
Yoshiyuki Ikegami ◽  
Akihiko Yoshida ◽  
Kenji Koori ◽  
Kiyoyuki Watanabe ◽  
...  

1996 ◽  
Vol 118 (4) ◽  
pp. 792-799 ◽  
Author(s):  
E. P. Vlasic ◽  
S. Girgis ◽  
S. H. Moustapha

This paper describes the design and performance of a high work single-stage research turbine with a pressure ratio of 5.0, a stage loading of 2.2, and cooled stator and rotor. Tests were carried out in a cold flow rig and as part of a gas generator facility. The performance of the turbine was assessed, through measurements of reaction, rotor exit conditions and efficiency, with and without airfoil cooling. The measured cooled efficiency in the cold rig was 79.9 percent, which, after correcting for temperature and measuring plane location, matched reasonably well the efficiency of 81.5 percent in the gas generator test. The effect of cooling, as measured in the cold rig, was to reduce the turbine efficiency by 2.1 percent. A part-load turbine map was obtained at 100, 110, and 118 percent design speed and at 3.9, 5.0, and 6.0 pressure ratio. The influence of speed and the limit load pattern for transonic turbines are discussed. The effect of the downstream measuring distance on the calculated efficiency was determined using three different locations. An efficiency drop of 3.2 percent was measured between the rotor trailing edge plane and a distance four chords downstream.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
An Wang ◽  
Qinghua Zeng

The load characteristics for the flow regulator of a solid ducted rocket are discussed in this paper. The mechanism and the influence factor of the load in the flow regulator were studied both theoretically and experimentally, and the system load and the working load were divided according to the mechanism. Additionally, the load influence on the working quality of the flow regulator and the ducted rocket were analyzed. System modeling of the flow regulator was carried out based on the working mechanism of the gas generator and the Stribeck friction model, and models of the actuator, gas generator, and load were built. Furthermore, considering the identification of the model parameters and the inapplicability of the conventional Stribeck identification method to the flow regulator, a new Stribeck model parameter identification method was proposed. A sine wave was used as the signal source, and specially designed devices were used to accomplish the switch of the working condition. Through the use of the genetic algorithm, the rotational inertia and parameters of the system load and working load were identified by stages. Finally, the validation of the identification method was carried out with a simulation.


Author(s):  
Shiyao Li ◽  
Zhenlin Li ◽  
Ning Huang

Accurate performance simulation can provide operating parameters and performance parameters for the gas turbine’s optimization, maintenance, and fault diagnosis. However, the components maps necessary for performance simulation are not publically available. In addition, the same type of gas turbine has slightly different component operating characteristics due to components′ variations in status and assembly tolerance. These causes bring real difficulties to the research of performance simulation. In order to obtain accurate components characteristics and performance simulation results, the original or generic components maps should be modified by the scaling factors. In the process of calculating scaling factors, the simulation model is applied repeatedly to determine the engine’s actual performance parameters until the simulated gas path thermal parameters are compatible with the actual measureable data. This paper introduces a new adaptation method and substitutes the calculation model with the simulation model in the adaptation process. It directly calculates the mass flow rate, isentropic efficiency, and pressure ratio of compressor and turbine based on measureable parameters such as gas path temperature, pressure, fuel component and mass flow rate. Moreover, this paper introduces the virtual gas generator model that enhances the applicability of calculation model based performance adaptation method on gas generators with different structures. This method has been applied to GE PGT25+ gas generator (single-spool) and RR RB211-24G gas generator (double-spool). Compared with the simulation model used in adaptation process, performance calculation model is much simpler and less time consuming.


1999 ◽  
Author(s):  
Takeshi Kudora ◽  
Rui Hirokawa ◽  
Hiroaki Matsuda ◽  
Kazuhisa Okamoto ◽  
Shoichiro Mihara ◽  
...  
Keyword(s):  

2021 ◽  
Author(s):  
André L. S. Andade ◽  
Osvaldo J. Venturini ◽  
Vladimir R. M. Cobas ◽  
Vinicius Zimmerman Silva

Abstract In order to increase the flexibility and performance of gas turbines, generally their manufacturers and research centers involved in their development are constantly seeking the expansion of their operational envelope as well as their efficiency, making the engine more dynamic, less polluting and able to respond promptly to variations in load demands. An important aspect that should be considered when analyzing these prime movers is the assessment of its behavior under transients due to load changes, which can be accomplished through the development of a detailed, accurate and effective computational model. Considering this scenario, the present work aims to develop a model for the simulation and analysis of the dynamic behavior of stationary gas turbines. The engine considered in this analysis has a nominal capacity of 30.7 MW (ISO conditions) and is composed by a two-spool gas generator and a free power turbine. The model was developed using T-MATS, an integrated Simulink/Matlab toolbox, develop by NASA. The gas turbine was evaluated under both permanent and transient regimes and each one of its component was analyzed individually. The assessment made it possible to determine the engine performance parameters such as efficiency, heat rate and specific fuel consumption and its operational limits (surge limits, stall, turbine inlet temperatures, etc.) under different load conditions and regimes. The results obtained were compared with available field data, and the relative deviations for the considered parameters were all lower than 1%.


Author(s):  
A. N. Nazare ◽  
S. N. Asthana ◽  
P. G. Shrotri ◽  
Haridwar Singh
Keyword(s):  

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