STUDY ON THE NECESSITY OF MEASURING THE ROUNDNESS OF NOZZLE THROAT

2021 ◽  
Author(s):  
Y. Zhao ◽  
M. Sun ◽  
Y. Li
Keyword(s):  
Nozzle Throat

UCBO Hydraulic Oil and Application on Hydraulic Measurement for Laval Nozzle Throat Diameter

2015 ◽  
Vol 667 ◽  
pp. 449-454
Author(s):  
Yang Hong ◽  
Xiang Zhang ◽  
Dong Xiang Shao ◽  
Guang Lin Wang ◽  
Li Sun
Keyword(s):  
Laval Nozzle ◽  
Oxidation Stability ◽  
Measurement Model ◽  
Diameter Measurement ◽  
Liquid Pressure ◽  
Nozzle Throat ◽  
Hydraulic Oil ◽  
Temperature Performance ◽  
Measurement Principle ◽  
Throat Diameter

This paper proposes a hydraulic measurement model for measuring the Laval nozzle throat diameter size. Based on measurement principle of liquid pressure – flowrate, we can get the size of Laval nozzle throat diameter by measuring the fluid flowrate through hydraulic measurement model at the fixed pressure. With good viscosity-temperature performance, low temperature performance and oxidation stability, UCBO aviation hydraulic oil is selected as the measuring medium. In the hydraulic measurement model, the diameter of the mandrel which can be regarded as gauge will directly affect the sensitivity of diameter measurement. Therefore we need to optimize the design of the mandrel of the hydraulic model.

Analysis of endurance of the material in the nozzle throat in high-pressure gas-dynamic facilities

2012 ◽  
Vol 53 (6) ◽  
pp. 954-960
Author(s):  
M. E. Topchiyan ◽  
V. I. Pinakov ◽  
A. A. Meshcheryakov ◽  
V. N. Rychkov
Keyword(s):  
High Pressure ◽  
Nozzle Throat ◽  
Gas Dynamic

Effect of porosity zoning and matrix material on the performance of self-cooled nozzle throat inserts.

1966 ◽  
Vol 3 (7) ◽  
pp. 1138-1140
Author(s):  
J. D. SEADER ◽  
W. J. RIVERS ◽  
R. J. INGRAM
Keyword(s):  
Matrix Material ◽  
Nozzle Throat

Analysis of Effect of Advanced Technique Configurations on Overall Performance of High Bypass Turbofan Engine

2014 ◽  
Author(s):  
Liu Jian Jun
Keyword(s):  
Air Flow ◽  
Engine Performance ◽  
Performance Model ◽  
Direct Drive ◽  
Nozzle Throat ◽  
Advanced Technique ◽  
Turbofan Engine ◽  
Overall Performance ◽  
Cooling Air Flow ◽  
Cooling Air

An analytical study was undertaken using the performance model of a two spool direct drive high BPR 300kN thrust turbofan engine, to investigate the effects of advanced configurations on overall engine performance. These include variable bypass nozzle, variable cooling air flow and more electric technique. For variable bypass nozzle, analysis on performance of outer fan at different conditions indicates that different operating points cannot meet optimal performance at the same time if the bypass nozzle area kept a constant. By changing bypass nozzle throat area at different states, outer fan operating point moves to the location where airflow and efficiency are more appropriate, and have enough margin away from surge line. As a result, the range of variable area of bypass nozzle throat is determined which ensures engine having a low SFC and adequate stability. For variable cooling airflow, configuration of turbine cooling air flow extraction and methodology for obtaining change of cooling airflow are investigated. Then, base on temperature analysis of turbine vane and blade and resistance of cooling airflow, reduction of cooling airflow is determined. Finally, using performance model which considering effect of cooling air flow on work and efficiency of turbine, variable cooling airflow effect on overall performance is analyzed. For more electric technique, the main characteristic is to use power off-take instead of overboard air extraction. Power off-take and air extraction effect on overall performance of high bypass turbofan engine is compared. Investigation demonstrates that power offtake will have less SFC.

scholarly journals The influence of Laval nozzle throat size on supersonic molecular beam injection

2014 ◽  
Vol 22 (2) ◽  
pp. 118-121 ◽  
Author(s):  
Xinkui He ◽  
Xianfu Feng ◽  
Mingmin Zhong ◽  
Fujun Gou ◽  
Shuiquan Deng ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Laval Nozzle ◽  
Nozzle Throat ◽  
Supersonic Molecular Beam ◽  
Beam Injection

scholarly journals Comprehensive Data Reduction for N2O/HDPE Hybrid Rocket Motor Performance Evaluation

Aerospace ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 45 ◽  
Author(s):  
Kamps ◽  
Sakurai ◽  
Saito ◽  
Nagata
Keyword(s):  
Data Reduction ◽  
Rocket Motor ◽  
Hybrid Rocket ◽  
Nozzle Throat ◽  
Transient Time ◽  
Mass Consumption ◽  
Fuel Mass ◽  
Hybrid Rocket Motor ◽  
Novel Approach ◽  
Nozzle Erosion

Static firing tests of a hybrid rocket motor using liquid nitrous oxide (N2O) as the oxidizer and high-density polyethylene (HPDE) as the fuel are analyzed using a novel approach to data reduction that allows histories for fuel mass consumption, nozzle throat erosion, characteristic exhaust velocity (c*) efficiency, and nozzle throat wall temperature to be determined experimentally. This is done by firing a motor under the same conditions six times, varying only the burn time. Results show that fuel mass consumption was nearly perfectly repeatable, whereas the magnitude and timing of nozzle throat erosion was not. Correlations of the fuel regression rate result in oxidizer port mass flux exponents of 0.62 and 0.76. There is a transient time in the c* efficiency histories of around 2.5 s, after which c* efficiency remains relatively constant, even in the case of excessive nozzle throat erosion. Although nozzle erosion was not repeatable, the erosion onset factors were similar between tests, and greater than values in previous research in which oxygen was used as the oxidizer. Lastly, nozzle erosion rates exceed 0.15 mm/s for chamber pressures of 4 to 5 MPa.

Optimizing Separate Exhaust Turbofans for Cruise Specific Fuel Consumption

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Syed J. Khalid
Keyword(s):  
Fuel Consumption ◽  
Control Algorithm ◽  
Velocity Ratio ◽  
Transmission Efficiency ◽  
Specific Fuel Consumption ◽  
Variable Geometry ◽  
Nozzle Throat ◽  
Propulsive Efficiency ◽  
Turbofan Engines ◽  
Bypass Ratio

Cruise specific fuel consumption (SFC) of turbofan engines is a key metric for increasing airline profitability and for reducing CO2 emissions. Although increasing design bypass ratio (BPR) of separate exhaust turbofan configurations improves cruise SFC, further improvements can be obtained with online control actuated variable geometry modulations of bypass nozzle throat area, core nozzle throat area, and compressor variable vanes (CVV/CVG). The scope of this paper is to show only the benefits possible, and the process used in determining those benefits, and not to suggest any particular control algorithm for searching the best combination of the control effectors. A parametric cycle study indicated that the effector modulations could increase the cruise BPR, core efficiency, transmission efficiency, propulsive efficiency, and ideal velocity ratio resulting in a cruise SFC improvement of as much as 2.6% depending upon the engine configuration. The changes in these metrics with control effector variations will be presented. Scheduling of CVV is already possible in legacy digital controls; perturbation to this schedule and modulation of nozzle areas should be explored in light of the low bandwidth requirements at steady-state cruise conditions.

scholarly journals Design of converging-diverging nozzles with constant-radius centerbody

2019 ◽  
Vol 12 (2) ◽  
pp. 191-201
Author(s):  
Andreas K. Flock ◽  
Ali Gülhan
Keyword(s):  
Method Of Characteristics ◽  
Noise Generation ◽  
Exit Plane ◽  
Nozzle Throat ◽  
Wake Flows ◽  
Constant Radius ◽  
Supersonic Regime ◽  
Flow Phenomena ◽  
Fundamental Research ◽  
Good Agreement

AbstractSeveral flow phenomena, such as recirculating wake flows or noise generation, occur in aerodynamic configurations with backward facing steps. In this context, subsonic nozzles with constant-radius centerbodies exist, which enable fundamental research of these phenomena for $$M < 1$$M<1. For the supersonic regime, however, the existing database and knowledge are limited. Therefore, this work presents a design approach for a converging-diverging nozzle with constant-radius centerbody. For the nozzle throat, Sauer’s method is modified to include a centerbody. The method of characteristics is used for the subsequent supersonic portion. Comparing the analytical calculations to numerical simulations results in very good agreement and therefore underlines the feasibility of the chosen approach. Viscosity reduced the Mach number on the exit plane by 1.0–1.2% and therefore had little influence.

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