Search results

This paper aims to present the design of a particular non-reactive test rig for combustion swirlers and first stage turbine nozzles. The test rig is required for important experimental activities aimed at the optimization of a specific class of gas turbines.

A multi-disciplinary team performed the design process by following a tailored design approach, which has been developed for the specific case. The design outcomes allowed to build a fully functional test rig to be introduced in a test cell and then to perform preliminary experiments about the fluid dynamic behaviour of the turbine elements.

The followed design approach allowed to efficiently perform the task, by supporting the information exchange among the different subjects involved in both the conceptual and the embodiment design of the test rig. Additionally, the performed experiments allowed to achieve a final configuration that makes the test rig a valuable test case for combustor-turbine interaction studies.

The study described in this paper is focused on the design of a specific test rig, used for first validation tests. However, the achieved results (both in terms of design and test) constitutes the underpinning of the in-depth investigations to be performed in the next steps of the experimental campaign.

To the best of the authors’ knowledge, the present paper is the first one that comprehensively describes the design activity of an experimental test rig for turbine application, also providing indications about the specific methodological procedure used to manage the process.

The helical spring lock washer (HSLW) is a part of nut bolt joint assembly used in different industries like automobile, aerospace, mechanical, chemical, electrical, electronics, etc. It works as a part of temporary joint and plays important role in loosening behavior of assembly under dynamic (vibrations) conditions. Thus, the purpose of this paper is to investigate the performance of HSLW under different controlled operating conditions in order to satisfy its functional requirement.

In the present investigation, a novel test rig is designed and developed to determine the load-deflection characteristics of HSLWs. The test rig facilitates the controlled linear displacement of the HSLW with predetermined angular rotation of the handle gives the corresponding reaction load on the display. Additionally, the repeatability and reproducibility of the test rig was carried out.

The newly designed and developed test rig is capable enough to differentiate the load-deflection characteristics during compressive loading and unloading of HSLWs. Additionally, the loss of strain energy can be determined from the load-deflection characteristics of HSLW.

The present test rig is designed and developed to investigate the load-deflection characteristics under compressive loading and unloading of HSLW. The test rig has least count of 0.4905 N for load measurement and 0.01389 mm for linear displacement.

The purpose of this work is to optimize the monitoring of vibrations on dynamometric test rigs for railway brakes. This is a quite demanding application considering the continuous increase of performances of high-speed trains that involve higher testing specifications for brake pads and disks.

In this work, authors propose a mixed approach in which relatively simple finite element models are used to support the optimization of a diagnostic system that is used to monitor vibration levels and rotor-dynamical behavior of the machine. The model is calibrated with experimental data recorded on the same rig that must be identified and monitored. The whole process is optimized to not interfere with normal operations of the rig, using common inertial sensor and tools and are available as standard instrumentation for this kind of applications. So at the end all the calibration activities can be performed normally without interrupting the activities of the rig introducing additional costs due to system unavailability.

Proposed approach was able to identify in a very simple and fast way the vibrational behavior of the investigated rig, also giving precious information concerning the anisotropic behavior of supports and their damping. All these data are quite difficult to be found in technical literature because they are quite sensitive to assembly tolerances and to many other factors. Dynamometric test rigs are an important application widely diffused for both road and rail vehicles. Also proposed procedure can be easily extended and generalized to a wide value of machine with horizontal rotors.

Most of the studies in literature are referred to electrical motors or turbomachines operating with relatively slow transients and constant inertial properties. For investigated machines both these conditions are not verified, making the proposed application quite unusual and original with respect to current application. At the same time, there is a wide variety of special machines that are usually marginally covered by standard testing methodologies to which the proposed approach can be successfully extended.

Fretting wear takes place when two contacting solid surfaces are subjected to relatively small amplitude oscillatory motion in the order of a few microns. The purpose of this paper is the design and manufacture of a fretting wear test rig that can analyze fretting wear on journal bearings.

This study included the manufacturing and operating principles of the test rig. In the test rig, the shaft was fixed and vibrational motion was given to the bearing housing. Vibration motion the amplitude of which could be adjusted was used on the test rig. The vibration motion was applied to a two-piece journal bearing on a fixed shaft supported from both ends.

Vibration amplitude was provided by a micro vibration engine (motor) to be under 100 μm.

Also, scanning electron microscopy, energy dispersive X-ray and X-ray diffraction analyses of the samples were investigated.

THE considerable difficulties encountered in designing a test rig which would allow of unbroken fuel supply from tanks whose attitude was being changed continuously was successfully overcome.

The purpose of this paper is to ascertain the stab resistance characteristics of a series of planar and articulated laser sintered (LS) samples, in accordance with the United Kingdom Home Office Scientific Development Branch (HOSDB) Body Armour Standard – Publication 39/07.

A series of LS planar samples were manufactured using an EOS P100 Formiga system, manufactured from 100 per cent virgin or a 50:50 mix of recycled and virgin Nylon (PA2200), ranging in thickness from 1‐10 mm. All planar samples were stab tested to the HOSDB knife‐resistance (KR) level one impact energy of 24 Joules, using an in‐house manufactured HOSDB guided rail drop test impact rig and standardised knives. Penetration through the underside of each sample was measured and recorded. These results were then used to develop an articulated, additive manufactured (AM) scale textile – LS from a 50:50 mix of recycled and virgin PA2200 powder. These samples were then tested using the aforementioned impact rig and stab impact energy.

The research demonstrated that while virgin PA2200 sample required a minimum thickness of 8 mm to achieve stab‐resistance below the HOSDB maximum penetration limit of 7 mm, this figure can be reduced to 5.6 mm when manufacturing LS planar samples from a 50:50 mix of virgin and recycled PA2200. Results from stab testing the articulated samples indicated a successful AM textile‐like design, with a maximum knife penetration of 1.6 mm – below the 7 mm HOSDB limit.

The paper describes a unique application of AM technologies for the manufacture of high‐performance stab resistant AM textiles.

MOST aircraft manufacturers would like to be able to check completely the functioning of all electrical installations while the aircraft is still in the rigging shop and without having to start the engines. Some tests, such as those for continuity of circuits and for “earths,” have for long been made at an early stage in the assembly; and much thought has, without doubt, gone on ways and means of increasing the amount of testing which can be done without running the engines.

This paper aims to design and manufacture a wear-test rig performing reciprocating movement that is more relevant to the elevator brake system. Also, a sample test result that was conducted in this experimental set-up is presented to evaluate the tribological properties of the brake linings of the elevator system that are activated in emergencies.

The brake linings are some of the most important security elements in elevators. The friction and wear properties of these brake linings have great importance for both safety and comfort. Elevator brake linings are often used in conjunction with guided rails under dry and boundary lubrication conditions. Therefore, friction coefficient and wear types occurring in the brake linings may be different. The tribological properties of the brake lining material in the literature are generally identified using a pin-on-disc wear-tester. The pin is contacted by rotating a disc in this wear-test rig. However, as the brake linings and guide rails do not have a reciprocating movement (linear translational motion) on each other, this wear-test rig is not suitable for brake linings and guide rails in the elevator system.

A sample test result that was conducted in this experimental set-up is presented to evaluate the tribological properties of the brake linings of the elevator system that are activated in emergencies. In these experiments, three different brake lining materials that are widely used in the elevator car guide rails in Turkey were tested under different speeds and loads.

The paper provides information about how to evaluate the tribological properties of the brake linings of the elevator system that are activated in emergencies. Also, it offers practical help for the manufacturer and researcher in the elevator sector.

TWENTY‐ONE years devoted to the development of ejection seats, 24,000 seats built for more than forty nations and now one thousand lives saved—that is the proud record of the Martin‐Baker Aircraft Company. To coincide with these achievements, the following article describes the technical development of the range of seats—from the first swinging arm concept through the early manually‐operated seat to the rocket‐assisted completely automatic zero/zero ejection seats of today. From whatever standpoint Martin‐Baker's record is examined, the result is impressive. In terms of mechanical engineering, a series of ingenious features allied to robust design have resulted in ejection seats of unparalleled performance yet renowned for their simplicity and reliability. In terms of sales, this comparatively small firm has, in effect, conquered the world and won substantial export contracts—not least those for over 7,000 seats for the United States armed forces. In human terms, the company has won the grateful thanks of all those aircrew members—a long roll of highly‐skilled and dedicated young men whom some might call the cream of manhood—who but for Martin‐Baker ejection seats would have perished. Small wonder that the name Martin‐Baker has become synonymous with successful ejection.

Froude Engineering has completed the installation and commissioning of an advanced helicopter transmission test rig at Westland Helicopters Ltd., Yeovil, which is unique in Britain. The contract worth £2m. to Froude Engineering, the Worcester‐based member of the Redman Heenan International group of companies, represents more than two years of work which began with a feasibility study of more precise and more reliable methods for testing complete helicopter transmissions as well as their components.