Automated selection and assembly of sets of blades for jet engine compressors and turbines

The increase in engine efficiency to be gained by substituting a floated close running air seal at the high pressure end of large jet engine compressors, in place of the labyrinth seal, has prompted an intensive effort to design such seals for experimental evaluation. This paper describes the design of both a radial and an axial version in which multiple segmental shoes are floated 0.001 in. from the high speed runner surface. In the radial version, the shoes are free to float radially in order to follow runner runout. In the axial version, the shoes track the runner runout by floating axially in a carrier which moves to accommodate 0.4 inch of differential expansion. Floating is achieved through hydrostatic action sustained by the pressure difference across the seal. A shrouded Rayleigh step profile on the primary (high speed rubbing) seal surface provides additional protection. An order of magnitude reduction in leakage rate is predicted.

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Bleed Airflow CFD Modeling in Aerodynamics Simulations of Jet Engine Compressors

Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery ◽

10.1115/2001-gt-0544 ◽

2001 ◽

Cited By ~ 3

Author(s):

Franck Conan ◽

Stephan Savarese

Keyword(s):

Boundary Condition ◽

Flow Rate ◽

Local Effect ◽

Cfd Modeling ◽

Flow Section ◽

Qualitative Comparison ◽

Analytical Geometry ◽

Jet Engine ◽

Experimental Database ◽

Engine Compressors

Several types of bleed airflow in jet engine compressors are required for both aircraft and engine operations. Since accessory, discharge or ventilation bleeds divert a significant percentage of the total input flow rate, it is compulsory to take these variations into account both in through-flow and in 3D Navier-Stokes compressor computations. While the former is straightforward to implement, which has been done for some time, several options are available for the three-dimensional case. The details of such models are most likely to have a local effect on the pressure and velocity fields distribution near the bleed section. Nevertheless, for the purpose of modeling the global effect of bleed flow magnitude on stage matching and overall aerodynamic stage performance, it is thought that a simple geometrical model of the bleed section combined with a simple outlet boundary condition will be accurate enough to provide a realistic representation of the actual compressor characteristics under various bleed flow rate conditions. Thus, our purpose in this study was to develop, implement and validate a simple model based upon both analytical geometry descriptions and outlet flow boundary conditions without any mesh modification or refinement with respect to the standard no-bleed calculations. The analytical description of bleed section is restricted to the intersection of the hub or casing with a set of radial cylinders or axisymetric slots, covering within manufacturing tolerance the known range of bleed section shapes. The physical boundary condition is applied at the intersection of the main flow path with the bleed duct or cavity outlet, ideally imposing a predefined exit flow rate. However, without access to an experimental database of engine bleed flow section measurements, only a qualitative comparison of the models with academic bleed flow experiments has been achieved. In order to assess the modeling scatter due to the details of the methods, two different models have been tested and validated against meridional flow computations, based upon compressor test results.

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Numerical solution of nonlinear ℋ/sub 2/ and ℋ/sub ∞/ control problems with application to jet engine compressors

IEEE Transactions on Control Systems Technology ◽

10.1109/87.817695 ◽

2000 ◽

Vol 8 (1) ◽

pp. 98-111 ◽

Cited By ~ 13

Author(s):

M. Hardt ◽

J.W. Helton ◽

K. Kreutz-Delgado

Keyword(s):

Numerical Solution ◽

Control Problems ◽

Jet Engine ◽

Engine Compressors

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Human resources sensitivity to system design tradeoff alternatives: Feasibility test with jet engine data.

PsycEXTRA Dataset ◽

10.1037/e440862004-001 ◽

1973 ◽

Author(s):

William B. Askren ◽

Kenneth D. Korkan ◽

George W. Watts

Keyword(s):

Human Resources ◽

System Design ◽

Jet Engine ◽

Feasibility Test

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DETERMINATION OF THE TYPE OF A SINGLE-USE GRENADE LAUNCHER BASED ON ITS COMPOSITE PARTS AND FRAGMENTS OF REACTIVE GRENADE FOUND AT THE PLACE OF ACCIDENT

Theory and Practice of Forensic Science and Criminalistics ◽

10.32353/khrife.2017.31 ◽

2017 ◽

Vol 17 ◽

pp. 245-252

Author(s):

V. V. Somov

Keyword(s):

Combustion Chamber ◽

Structural Features ◽

Outlet Section ◽

Technical Expertise ◽

Jet Engine ◽

Size Ofthe ◽

Single Use ◽

Nozzle Block ◽

Considerable Damage

In carrying out an investigation into the explosion, among others, the investigative version of the use of a single-use reactive grenade launcher is being considered. The most common for criminal explosions are applied grenade launchers RPG-18, RPG-22, RPG-26. Their use is due to a number of such properties as small size and weight, which makes it possible to transfer them covertly, the range of the shot significantly exceeding the range of the hand grenade throw, the high detonating effect of the rocket grenade explosion. The single-use rocket launchers are generally of the same design. Their differences are in the features of the components construction and dimensional characteristics, which are given in the article. On the basis of expert practice, details ofgrenade launchers that remain at the site of the explosion and have the least damage are determined. These details are the objects of investigation of the explosion technical expertise. These objects include launchers of grenade launchers and rocket parts ofjet grenades. The design features of the launchers, their dimensional characteristics and marking symbols make it possible to determine their belonging to a specific type of jet grenade launchers. Missile parts of jet grenades differ in the form of the combustion chamber of the jet engine, nozzle, in the size ofthe outlet section of the nozzle, in the form and size of the stabilizerfeathers. To determine the belonging of the rocket part of the grenade to a specific type ofjet grenade launcher, it’s necessary to establish a set of structural features and dimensional characteristics. At considerable damage of the combustion chamber of the jet engine, as a rule, the nozzle block remains intact that allows to define diameter of critical section of a nozzle, and on it to establish type of the used single-use grenade launcher.

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