Numerical Behaviour of Primary Air Flow Field of a Swirl Injector Under High Pressure and High Temperature Condition

2021 ◽  
Author(s):  
Rampada Rana ◽  
Muthuveerappan Nagalingam ◽  
Saptarshi Basu
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Flow Field ◽  
Spatial Scales ◽  
Atmospheric Condition ◽  
Fixed Time ◽  
Combustion Efficiency ◽  
Computational Domain ◽  
Time Step ◽  
Swirl Injector

Abstract Injector plays pivotal role to meet better combustion performances requirements in terms of combustion efficiency, flame stability, ignition, lower emissions etc. In a multi-swirler injector, the primary swirler mainly dictates the airflow field inside and some extend outside the injector. Present CFD studies have been attempted to characterize the flow field of a swirl injector consisting of conical nozzle fitted with single radial swirler at its upstream. Studies are performed at high pressure and high temperature resulting to high density (increased by around 9 times compared to atmospheric condition) and its impact on the flow field in terms of location of energetic zones useful for fuel atomization. Since direct effect of increase in density lead to increase in turbulence which is helpful for mixing and atomization, this study is helpful to capture the same. Embedded LES based hybrid model has been used where the computational domain divided into 3 zones which are seamlessly connected by capturing the interface fluid dynamics. In LES zone, both the time and spatial scales have been resolved by suitably refining the grids. Analysis is carried out with CFL no. around 2, fixed time step of 1 micro second. The analysis is reasonably able to capture various unsteadiness (PVC, CTRZ, frequencies etc. useful for the atomization of the liquid fuel) which are not available beforehand.

Influences of Ignition Timing, Spark Plug and Intake Port Locations on the Combustion Performance of a Simulated Rotary Engine

2016 ◽  
Vol 32 (5) ◽  
pp. 579-591 ◽  
Author(s):  
P.-W. Hwang ◽  
X.-C. Chen ◽  
H.-C. Cheng
Keyword(s):  
Flow Field ◽  
Combustion Chamber ◽  
Combustion Efficiency ◽  
Intake Port ◽  
Computational Domain ◽  
Ignition Timing ◽  
Combustion Chambers ◽  
Combustion Performance ◽  
Rotary Engine ◽  
Spark Plug

AbstractThe purpose of this paper is to study the flow field of the combustion chamber in a simulated rotary engine by using a computational approach. A dynamic mesh technique is employed to overcome the moving and shape varying computational domain inside the combustion chambers as the rotor is spinning. The key parameters include spark plug timing, leading side spark plug location and intake port location, which are used to investigate their influences on flow field and combustion performance of a rotary engine. It was discovered, with a dual spark plug configuration, that better flame propagation could be obtained through the change of ignition timing. In addition, to change the leading side spark plug location, it was also found that combustion efficiency is improved by shortening the distance from the top dead center (TDC) center line, which is consistent with available experimental results. This research also discovered that the intake port should be properly located in order to prevent pressure loss in the combustion chamber during the compression stroke.

RANS Based Iso-Thermal CFD Analysis of the Flow Field Created by a Radial Swirler in a Conical Nozzle

2019 ◽  
Author(s):  
Rampada Rana ◽  
Sonu Kumar ◽  
Nagalingam Muthuveerappan
Keyword(s):  
Flow Field ◽  
Maximum Flow ◽  
Field Studies ◽  
Combustion Efficiency ◽  
Computational Domain ◽  
Conical Nozzle ◽  
Ansys Fluent ◽  
Upstream Direction ◽  
Ignition Characteristics ◽  
The Impact

Abstract Improvement of specific fuel consumption and specific thrust of gas turbine engines have necessitated to have better combustion performances requirements in terms of combustion efficiency, flame stability, better ignition characteristics, lower emissions etc. Injector designs play a very pivotal role to meet the above requirements. In this paper steady state flow field studies have been carried out in a conical nozzle fitted with single swirler which is the fundamental part of a typical injector. The aspects of the flow field both inside and outside the injector have been captured by using RANS based calculations of commercial software Ansys Fluent. The computational domain extends from 500mm in the upstream direction and the exit flow of the nozzle is allowed to meet on to a domain of length more than 2000mm. The downstream domain is so chosen that the impact of the wall on to the evaluation of the flow field is found to be negligible resembling the flow field studies in open atmosphere. Realizable k-ε turbulent model and standard wall function were used with wall y+ extended from 30 onwards. The study shows a distinct feature of maximum flow velocity at the exit of the injector lip apart from the presence of regular re-circulation bubble at the exit of the injector.

Wake-Wake Interactions and its Potential for Clocking in a Transonic High Pressure Turbine

2001 ◽  
Author(s):  
Frank Hummel
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Flow Direction ◽  
Numerical Procedure ◽  
Flow Simulation ◽  
Suction Side ◽  
Frame Of Reference ◽  
High Pressure Turbine ◽  
Time Step ◽  
Trailing Edge

Two-dimensional unsteady Navier-Stokes calculations of a transonic single stage high pressure turbine were carried out with emphasis on the flow field behind the rotor. Detailed validation of the numerical procedure with experimental data showed excellent agreement in both time-averaged and time-resolved flow quantities. The numerical time-step as well as the grid resolution allowed the prediction of the Kármán vortex streets of both stator and rotor. Therefore the influence of the vorticity shed from the stator on the vortex street of the rotor is detectable. It was found that certain vortices in the rotor wake are enhanced while others are diminished by passing stator wake segments. A schematic of this process is presented. In the relative frame of reference the rotor is operating in a transonic flow field with shocks at the suction side trailing edge. These shocks interact with both rotor and stator wakes. It was found that a shock-modulation occurs in time and space due to the stator wake passing. In the absolute frame of reference behind the rotor a 50% variation in shock strength is observed according to the circumferential or clocking position. Furthermore a substantial weakening of the rotor suction side trailing edge shock in flow direction is detected in an unsteady flow simulation when compared to a steady state calculation which is caused by convection of upstream stator wake segments. The physics of the mentioned unsteady phenomena as well as their influence on design are discussed.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

YSS YXM4

Alloy Digest ◽  
2019 ◽  
Vol 68 (11) ◽  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Physical Properties ◽  
Tool Steel ◽  
High Speed ◽  
Temperature Performance

Abstract YSS YXM4 is a cobalt-alloyed molybdenum high-speed tool steel with resistance to abrasion, seizure, and deformation under high pressure. This datasheet provides information on composition, physical properties, and hardness. It also includes information on high temperature performance. Filing Code: TS-780. Producer or source: Hitachi Metals America, Ltd.

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