Computational and Experimental Testing of Aircraft Bell Nozzle: Technical Note

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
F. Ferdaus ◽  
R. Ganapathi
Keyword(s):  
Mach Number ◽  
Supersonic Flow ◽  
Experimental Testing ◽  
Technical Note ◽  
Aviation Industry ◽  
Raspberry Pi ◽  
Cfd Analysis ◽  
Nozzle Design ◽  
Hypersonic Speed ◽  
Nozzle Pressure

In order to gain the supersonic and hypersonic speed, the nozzle plays a major role in the aviation industry. Based on the nozzle design, the required mach number can be calculated. In this paper, the convergent divergent bell nozzle which is basically used for the supersonic flow is analysed and designed using CATIA Software. The mesh of the designed nozzle is carried out in ANSA and then analysed using CFD. Different nozzle designs are assessed through of CFD analysis to choose the best performing nozzle that can be manufactured for experiments. For the experimental test Raspberry Pi, pressure sensor and Python coding was developed to test bell nozzle pressure.

CFD Analysis of Aircraft Curved C-D Nozzle: Technical Note

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
F. Ferdaus ◽  
S. Sivaganesan ◽  
C. Dhanasekaran ◽  
G. Sathishkumar ◽  
S. Sivabalan
Keyword(s):  
Mach Number ◽  
Technical Note ◽  
Cfd Analysis ◽  
Flow Conditions ◽  
Flow Properties ◽  
Subsonic Flows ◽  
Gas Dynamic ◽  
Sonic Flow ◽  
Exit Mach Number ◽  
Gas Dynamic Equations

A nozzle for the aircraft can be designed by considering the exit Mach number. In order to get a premeditated Mach number, we need to convert pressure energy into kinetic energy by using a nozzle. Convergent nozzles are utilized for subsonic flows while Convergent-Divergent (C-D) nozzle is utilized for supersonic flows. Curved nozzle flow is accelerated from low subsonic to sonic velocity at the throat and further expanded to supersonic velocities at the exit, in a C-D nozzle. This paper details the relevancies on designing a curved nozzle to attain super-sonic flow and maximizing the optimal thrust and devoid of flow separation due to shock waves. The navigation of the flow must be parallel to the axis of the nozzle for achieving extreme thrust and proficiency. Based on the fundamental gas dynamic equations, this study aims to develop a theoretical approach for the calculation of the flow properties along the axis of the C-D Nozzle. The flow conditions were selected in consideration of the pressure, temperature and gases accessible at the exit of the combustion chamber.

Unsteady Numerical Simulation of Shock Systems in Vaneless Counter-Rotating Turbine

2005 ◽  
Author(s):  
Huishe Wang ◽  
Qingjun Zhao ◽  
Xiaolu Zhao ◽  
Jianzhong Xu
Keyword(s):  
Numerical Simulation ◽  
Mach Number ◽  
Leading Edge ◽  
Turbine Rotor ◽  
Nozzle Design ◽  
Suction Surface ◽  
Rotor Wake ◽  
Wake Interaction ◽  
Unsteady Numerical Simulation ◽  
Almost All

A detailed unsteady numerical simulation has been carried out to investigate the shock systems in the high pressure (HP) turbine rotor and unsteady shock-wake interaction between coupled blade rows in a 1+1/2 counter-rotating turbine (VCRT). For the VCRT HP rotor, due to the convergent-divergent nozzle design, along almost all the span, fishtail shock systems appear after the trailing edge, where the pitch averaged relative Mach number is exceeding the value of 1.4 and up to 1.5 approximately (except the both endwalls). A group of pressure waves create from the suction surface after about 60% axial chord in the VCRT HP rotor, and those waves interact with the inner-extending shock (IES). IES first impinges on the next HP rotor suction surface and its echo wave is strong enough and cannot be neglected, then the echo wave interacts with the HP rotor wake. Strongly influenced by the HP rotor wake and LP rotor, the HP rotor outer-extending shock (OES) varies periodically when moving from one LP rotor leading edge to the next. In VCRT, the relative Mach numbers in front of IES and OES are not equal, and in front of IES, the maximum relative Mach number is more than 2.0, but in front of OES, the maximum relative Mach number is less than 1.9. Moreover, behind IES and OES, the flow is supersonic. Though the shocks are intensified in VCRT, the loss resulted in by the shocks is acceptable, and the HP rotor using convergent-divergent nozzle design can obtain major benefits.

Investigation of Loss Impact From Production-Like Features in a Compressor Duct Under Engine Realistic Conditions

2017 ◽  
Author(s):  
Fredrik Wallin ◽  
Mark H. Ross ◽  
Max Rusche ◽  
Scott Morris ◽  
Steven Ray
Keyword(s):  
Surface Roughness ◽  
Total Pressure ◽  
Experimental Testing ◽  
Computational Grid ◽  
Test Facility ◽  
Pressure Probe ◽  
Cfd Analysis ◽  
Roughness Model ◽  
Geometrical Features ◽  
Real Geometry

An experimental and numerical investigation of the flow in a compressor duct with engine-realistic in-production features is presented in this paper. The experimental testing was conducted in the ND-FSCC test facility at University of Notre Dame, Indiana, USA. A baseline duct was also tested for back-to-back comparison. The ducts were heavily instrumented; duct inlet and exit flowfields were scanned using a five-hole pressure probe that provided total pressure, velocities and flow angles. Based on the five-hole probe total pressures, duct losses could be assessed. Furthermore the duct inlet boundary layers were traversed and turbulence intensity levels were assessed. For the CFD analysis of the production-like duct, a highly complex computational grid, resolving all the geometrical features present, was used. A previously validated surface roughness model was used to account for the cast aero-surfaces. Both experimental and numerical results show that there is a significant increase in loss for the production-like duct when compared to the baseline duct loss. The CFD results agree very well with experimental results for the baseline duct, which makes it possible to use the experimental data recorded for the production-like duct to validate CFD tools for real geometry effects, such as interface steps and surface roughness for example.

scholarly journals Звуковой удар от тонкого тела и локальных областей нагрева сверхзвукового набегающего потока

2021 ◽  
Vol 91 (4) ◽  
pp. 558
Author(s):  
А.В. Потапкин ◽  
Д.Ю. Москвичев
Keyword(s):  
Mach Number ◽  
Supersonic Flow ◽  
Free Stream ◽  
Local Heating ◽  
Air Flow ◽  
Sonic Boom ◽  
Incoming Flow ◽  
Combined Method ◽  
Cold Flow ◽  
Free Stream Mach Number

The problem of a sonic boom generated by a slender body and local regions of supersonic flow heating is solved numerically. The free-stream Mach number of the air flow is 2. The calculations are performed by a combined method of phantom bodies. The results show that local heating of the incoming flow can ensure sonic boom mitigation. The sonic boom level depends on the number of local regions of incoming flow heating. One region of flow heating can reduce the sonic boom by 20% as compared to the sonic boom level in the cold flow. Moreover, consecutive heating of the incoming flow in two regions provides sonic boom reduction by more than 30%.

On the breakdown of characteristics solutions in flows with vibrational relaxation

1967 ◽  
Vol 27 (1) ◽  
pp. 49-57 ◽  
Author(s):  
B. S. H. Rarity
Keyword(s):  
Relaxation Time ◽  
Mach Number ◽  
Supersonic Flow ◽  
Steady Flow ◽  
Speed Of Sound ◽  
Vibrational Relaxation ◽  
Precise Measure ◽  
Derivatives Of ◽  
Relaxing Gas ◽  
Flow Case

The breakdown of the characteristics solution in the neighbourhood of the leading frozen characteristic is investigated for the flow induced by a piston advancing with finite acceleration into a relaxing gas and for the steady supersonic flow of a relaxing gas into a smooth compressive corner. It is found that the point of breakdown moves outwards along the leading characteristic as the relaxation time decreases and that there is no breakdown of the solution on the leading characteristic if the gas has a sufficiently small, but non-zero, relaxation time. A precise measure of this relaxation time is derived. The paper deals only with points of breakdown determined by initial derivatives of the piston path or wall shape. In the steady-flow case, the Mach number based on the frozen speed of sound must be greater than unity.

Numerical Simulation of Supersonic Jet Control by Tabs with Slanted Perforation

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
G. Ezhilmaran ◽  
Suresh Chandra Khandai ◽  
Yogesh Kumar Sinha ◽  
S. Thanigaiarasu
Keyword(s):  
Numerical Simulation ◽  
Mach Number ◽  
Near Field ◽  
Pressure Ratio ◽  
Supersonic Jet ◽  
Pressure Gradients ◽  
Nozzle Pressure Ratio ◽  
Nozzle Pressure ◽  
Jet Control ◽  
Different Diameters

Abstract This paper presents the numerical simulation of Mach 1.5 supersonic jet with perforated tabs. The jet with straight perforation tab was compared with jets having slanted perforated tabs of different diameters. The perforation angles were kept as 0° and 10° with respect to the axis of the nozzle. The blockage areas of the tabs were 4.9 %, 4.9 % and 2.4 % for straight perforation, 10° slanted perforation ( {{{\Phi }}_{\ }} = 1.3 mm) and 10° slanted perforation ( {{{\Phi }}_{\ }} = 1.65 mm) respectively. The 3-D numerical simulations were carried out using the software. The mixing enhancements caused by these tabs were studied in the presence of adverse and favourable pressure gradients, corresponding to nozzle pressure ratio (NPR) of 3, 3.7 and 5. For Mach number 1.5 jet, NPR 3 corresponds to 18.92 % adverse pressure gradients and NPR 5 corresponds to 35.13 % favourable pressure gradients. The centerline Mach number of the jet with slanted perforations is found to decay at a faster rate than uncontrolled nozzle and jet with straight perforation tab. Mach number plots were obtained at both near-field and far field downstream locations. There is 25 % and 65 % reduction in jet core length were observed for the 0° and 10° perforated tabs respectively in comparison to uncontrolled jet.

Micro Gas Turbine Combustion Chamber Design and CFD Analysis

2004 ◽  
Author(s):  
Joao Parente ◽  
Giulio Mori ◽  
Viatcheslav V. Anisimov ◽  
Giulio Croce
Keyword(s):  
Gas Turbine ◽  
Design Process ◽  
Preliminary Analysis ◽  
Cooling System ◽  
System Development ◽  
Experimental Testing ◽  
Flame Temperature ◽  
Turbulence Models ◽  
Cfd Analysis ◽  
Micro Gas Turbine

In the framework of the non-standard fuel combustion research in micro-small turbomachinery, a newly designed micro gas turbine combustor for a 100-kWe power plant in CHP configuration is under development at the Ansaldo Ricerche facilities. Combustor design starts from a single silo chamber shape with two fuel lines, and is associated with a radial swirler flame stabiliser. Lean premix technique is adopted to control both flame temperature and NOx production. Combustor design process envisages two major steps, i.e. diagnostics-focussed design for methane only and experimentally validated design optimisation with suitable burner adaptation to non-standard fuels. The former step is over, as the first prototype design is ready for experimental testing. Step two is now beginning with a preliminary analysis of the burner adaptation to non-standard fuels. The present paper focuses on the first step of the combustor development. In particular, main design criteria for both burner and liner cooling system development are presented. Besides, design process control invoked both 2D and 3D CFD analysis. Two turbulence models, FLUENT standard k-ε model and Reynolds Stress Model (RSM), are refereed and the results compared. Here both a detailed analysis of CFD results and a preliminary analysis of main chemical kinetic phenomena are discussed.

Effect of Mach number on the efficiency of microwave energy deposition in supersonic flow

2016 ◽  
Vol 23 (5) ◽  
pp. 052305 ◽  
Author(s):  
V. A. Lashkov ◽  
A. G. Karpenko ◽  
R. S. Khoronzhuk ◽  
I. Ch. Mashek
Keyword(s):  
Mach Number ◽  
Supersonic Flow ◽  
Energy Deposition ◽  
Microwave Energy

Simulations of a low-boom, axisymmetric, external compression inlet

2013 ◽  
Vol 117 (1193) ◽  
pp. 709-726 ◽  
Author(s):  
T. Coyne ◽  
E. Loth ◽  
J. Koncsek ◽  
D. Davis ◽  
T. Conners ◽  
...  
Keyword(s):  
Mach Number ◽  
Experimental Testing ◽  
Navier Stokes ◽  
Supersonic Wind Tunnel ◽  
External Compression ◽  
Operational Characteristics ◽  
Theoretical Predictions ◽  
Mass Flow Rates ◽  
External Oblique ◽  
The Impact

Abstract Computational simulations have been used to study a new low-boom, axisymmetric, external compression supersonic inlet with an on-design Mach number of 1·7. The inlet incorporates a relaxed compression surface with a near-zero cowl angle to help reduce external oblique shock waves due to spillage and cowl geometry. To reduce mechanical complexity the inlet is designed with zero-bleed. To understand the impact on performance and shock overpressure caused by the inlet itself, several throat and diffuser designs were simulated. The computations utilised a Reynolds-averaged Navier-Stokes code. Inflow properties were held consistent with the operational characteristics of the NASA GRC 8′ × 6′ Supersonic Wind Tunnel (SWT) for experimental testing of the inlet of Mach 1·67 at a Reynolds number of 5·4 × 106. Stagnation pressure recovery performance for the baseline condition exceeded 94% at design mass flow rates, and reduced only slightly with increases in Mach number (consistent with theoretical predictions) and extension of cowl position. The simulations also showed that the relaxed compression surface combined with the near-zero cowl angle helps to significantly reduce external oblique shocks This is partly due to the reduced inlet spillage in combination with a reduced overall turning angle placed on the free-stream flow relative to the cowl shape.

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