MANUNET PROGRAM call 2018
contract (by Romanian Authority): 97/01.07.2019 - UEFISCDI
Coordinator: COMOTI Romanian research and Development Institute for Gas-Turbines, Romania
Partner: Grado Zero Innovation S.r.l., Italy
Partner: SC INAS SA, Romania
General and specific objectives
The general objective of the 3dBlade project falls within the scope of "MANUNET Call 2018" under "Additive manufacturing" topic, aiming to develop gas turbine individual rotor blades as hightech products, using the brand new 3d printing machine of the coordinator. The project is focused on the advantages provided by this technology, in terms of time and cost reduction, quality of built parts, novel shapes and geometric complexity not achievable through conventional fabrication techniques, thereby widening the horizon of design in the turbomachinery field by applying new technologies. Still, finishing operation on other high precision machines (such as 5 axis grinding) are envisaged since it is already known that assembling tolerances in the microns area cannot be directly obtained from the 3d printing process. During the project, the cast rotor blades (Figure 1b) of the free power turbine of an existing helicopter engine will be used as reference, since it is well known from all points of view: gas dynamic parameters (pressure, temperature, speed of rotation), material (nickel superalloy), qualification criteria (geometric and assembly tolerances, mechanical test) etc.
In order to achieve the general objective of the project, 3dBlade is structured to follow four specific objectives:
O1 - to conduct technology studies and to formulate a set of requirements for individual gas turbine rotor blades. There will be established a conformity matrix for gas turbines individual rotor blades taking into account a series of criteria such as the acceptance requirements for finished gas turbine parts, in terms of load parameters (stress and temperature) and dimensional tolerances, along with the control parameters of the 3d printing process itself (layer thickness, laser power, hatching distance etc.).
O2 - to select the proper material and to test the resulted mechanical properties in conditions similar to the functional ones (high stress under high temperature). There will be manufactured special designed samples to be tested following the severe requirements for gas turbine individual rotor blades.
O3 - to design the technology and to manufacture individual gas turbine rotor blades having improved performances in comparison to the existing ones (e.g. lower mass, higher durability).
O4 - to evaluate the proposed technology by validating the manufactured individual rotor blades in laboratory conditions close to the functional ones.
Project duration (by Romanian Authority): 18 month + 5 month prolongation due to COVID pandemics
Starting date (by Romanian Authority): 01.07.2019
Total project costs: 394350 EURO
Contact person: dr.ing. Valeriu VILAG, e-mail: firstname.lastname@example.org
Summary phase I:
The first phase of 3dBlade project had two main research directions:
-research concerning the additive manufacturing technologies and the limitations of the current printing machines, with focus on the printing machine to be used during the project;
-research concerning individual gas turbine rotor blades in order to formulate the set of requirements for them, no matter the manufacturing technology to be used.
There have been realized research activities concerning generic additive material technology with focus on the utilization for aerospace domain and the present day available materials. The printing machine of COMOTI as project coordinator was carefully studied in order to determine its limitation from materials point of view and from theoretical execution tolerances, according to the producer handbook and previous experience.
The set of requirements regarding individual gas turbine rotor blades, were based on studies regarding the functional conditions of these components which firstly determine the loads acting on the blades and, subsequently, their complex shape.
The optimization studies regarded the technological parameters that can be varied in order to obtain the desired results but also the way of imposing the optimization criteria in such cases that imply very new technologies.
Summary phase II:
The second phase of 3dBlade consists in the following research activities:
-material studies (selection and testing);
-gas turbine rotor blade design (CAD model and numerical simulations);
-rotor blades manufacturing trials.
During the research activities, the available printable materials were studied and the selection lead to INCONEL class type of materials. Specimens where printed using COMOTI's 3d printer and they have been tested at room and elevated temperature.
The CAD model of the individual gas turbine blade was realized using CAD design software and it was imported into stress and vibration software (FEA).
The mesh was constructed in such way to capture the geometric feature of the blade, especially in the fire tree section where the stresses are expected to be the highest.
A vibration analysis was also performed since it is an important requirement for such blades working at high rotational speed and being excited by all the upstream components of the engine.
The CAD model of the blade was exported in .stl neutral format and was printed in COMOTI and by GZI.
Summary phase III:
The third phase of 3dBlade consists in the following research activities:
-evaluation of the results.
The main part consisted in 3d scanning of the 3d printed turbine blades performed using COMOTI's equipment.
The observed deviations are satisfactory giving the fact that the evaluation was performed in "as printed" state, so without any post-processing.
-Turbine blade design methodology for a rocket engine turbopump, Cristian DOBROMIRESCU, Valeriu VILAG, Aerospace Europe Conference 2020, Bordeaux, France, 25-28 February 2020
-Study of 3D printing methods precision applied on turbine blades, Madalin DOMBROVSCHI, Cristian DOBROMIRESCU, Valeriu VILAG, Tiberius Florian FRIGIOIESCU, Marius DEACONU, Nicoleta Mirela POPA, Nichita Larisa MILODIN, 3rd International Conference on Emerging Technologies in Materials Engineering, Bucharest, Romania, 29-30 October 2020
-Additive manufacturing applications for aerospace Engineering, Cristian DOBROMIRESCU, Cosmin SUCIU, Madalin DOMBROVSCHI, Valeriu VILAG, 8th International Conference on Advanced Materials and Structures, Timi?oara, Romania, 9 October 2020
3d Printers Technology Studies and Requirements Formulation
Material Selection and Mechanical Testing
Gas Turbine Rotor Blade Design
Rotor Blades Manufacturing Trials
Technology validation and evaluation