logo_ciam_en-01.jpg   Central Institute of Aviation Motors
Eng

 Experimental Studies

23.10.53 обрез.jpg

Research efforts conducted at a certain stage of future hypersonic aircraft engine development require a great number of experimental studies of models, demonstration and experimental prototypes in an environment most closely resembling actual full-scale conditions. Besides that, altitude tests of aircraft engines at ground rigs are mandatory in the process of refinement of any type of an aircraft engine and must be conducted before flight tests, which make up the final stage of the entire product development program.

CIAM's research test rigs and plants are used for the following experimental research purposes:

‑ Studies of new designs of aircraft engines and components;

‑ Studies of engine cycles and the impact of various conditions on these cycles;

‑ Studies of combustion and ignition processes in combustion chambers;

‑ Studies of combustion chamber wall cooling processes;

‑ Studies of methods for improving the uniformity of gas dynamic field parameters in engines;

‑ Studies of new fuel types;

‑ Studies of engine and air intake operation margins during joint operation of engines and air intakes;

‑ Validation of bearing capacity margins of individual aircraft components under static and dynamic loads;

‑ Studies of conditions for combined operation of aircraft parts and components;

‑ Studies of new materials;

‑ Studies of performance of aircraft and engine component designs in high enthalpy flow;

‑ Studies of thermal protection utilization problems;

‑ Refinement and validation of mathematical models and calculation methods;

‑ Refinement of new advanced measurement instruments and methods;

‑ Refinement of new advanced design solutions for test bench process equipment;

– Refinement of rig and test process automatic control systems.

– Type approval testing of measurement instrumentation;

– Measurement instruments calibration;

– Metrological expert examination;

– Measurement method development and certification;

– Calibration work. 

Altitude/Speed and Environmental Testing of Air-Breathing Engines

Over 60 years of CIAM's experimental complex experience in testing full-scale GTE in simulated altitude and speed conditions proved high efficiency of its complex creation expanses. Over 900 engines have been tested at CIAM's altitude test rigs. CIAM's unique altitude rigs allow not only to test air-breathing engines, but also to conduct comprehensive studies aimed at establishing a research foundation for development of new aircraft prototypes.

CIAM's test rigs allow for engine cycle studies and refinement of full-scale aircraft air-breathing engines and their gas generators in simulated altitude and speed conditions, as well as conditions of airfields in various climatic zones and at high altitudes. Air-breathing engine tests are conducted with piping attached, or as part of a power plant streamed over by a subsonic or transonic airflow.
Testing allows determining the following characteristics:
– Altitude and speed performance;
– Strength properties;
– Gas dynamic and thermal properties of a cycle in steady and transition conditions, as well as along the aircraft trajectory in real time;
– Gas dynamic stability (stall) margins, including under conditions of thermal and aerodynamic disturbances at the inlet;
– Automated control system reliability and controllability;
– Starting performance;
– Altitude limits of lubrication systems and efficiency of de-icing systems, etc.
CIAM's complex of altitude/speed and climatic test rigs is the largest in Europe. It can be used for testing of running aircraft air-breathing engines with a maximum thrust of 25 tf, including turboprop, turboshaft, and auxiliary power units.

Testing of Aircraft Engine Components and Systems

For component-by-component refinement of engines, special rigs are used that enable testing of individual aircraft engine components.

CIAM's test rigs for testing of individual components of aircraft engines allow conducting experimental studies and tests of the following:

- Full-scale air-breathing engine compressors, their models, individual stages, cascades, and individual components in simulated operating conditions;

- Gas turbine engine combustion chambers;

- Full-scale turbines of aircraft engines, their models, and nozzle guide vanes;

- Multi-functional nozzle models;

- Components and units of control systems and fuel feed systems of gas turbine engines and gas turbine units.   

Aerospace Engine Studies and Testing

CIAM's test rigs for studies and refinement of the power units of future aerospace engine prototypes allow conducting experimental studies and tests of the following:

- Engines installed in the aircraft fuselage and blown over with a high-speed high enthalpy airflow;

- Full-scale test prototypes of combustion chambers of ramjet engines and their modules;

- Elements of thermally loaded areas air-breathing engines;

- Gas dynamic ducts of aerospace engines and their components;

- Components and systems of future air-breathing engines;

- Diffusers, gas dynamic tubes and their components;

- High altitude and high flow rate shutoff and control valves.

CIAM's rigs for aerospace engine testing have unique altitude and speed simulation capabilities that allow to conduct long-term and service life testing in steady-state conditions. 

Special and strength certification testing

The ever-increasing importance of engine strength and service life testing can be clearly illustrated by data from Rolls-Royce (M. Terrett. Civil Aerospace Briefing Presentation, June 18, 2003, Rolls-Royce). According to these data, the strength and service life testing accounted for about 10% of the total number of engine 3 tests in 1960, over 50% in 1970, and over 85% in 2000.
  CIAM's equipment for strength certification testing is designed for the following:
- Fatigue testing of prototypes and components;
- Low-cycle fatigue testing, static crack testing, and fatigue crack growth testing;
- Static and cycle testing of materials and components under unsteady loading and triaxial duty cycle loading conditions;
- Long-time and short-time strength testing and creep testing of materials at temperatures of up to 1900 K in the air;
- Thermomechanical stress cycle testing of turbine blades and other turbine components with simulated thermal stress conditions in the component’s critical section;
- Cryogenic testing of materials;
- Testing of materials in a hydrogen environment under tension, twisting, and internal pressure loading conditions;
- X-ray diffraction and metallographic examinations and scanning electron microscopy;
- Analysis of metallic, ceramic, and composite material performance at high temperatures;
- Examination of mechanical properties of high-temperature materials under tension, compression, bending, and shear in various environments;
- Analysis of strength, life, and dynamic performance of rotor components; case damage containing ability analysis;
- Vibration refinement of rotors;
- Rolling bearing and gear testing;
- Bird strike and blade separation testing of rotating rotors (impellers).
CIAM's rigs for special certification testing can be used for safety testing of not only aircraft engines, but also structural aircraft components (wings, stabilizers, cockpits, etc.) and power plants under icing, bird strike, foreign matter ingestion, and open flame (fire) conditions.

Strength testing is conducted:
- To prove safe engine operation capability as part of engine certification;
- For calculation method verification;
- To prove engine strength reliability in conditions that can be difficult to simulate by calculation analysis;
- To create a structural strength data bank for materials;
- To verify and optimize new design and process solutions.

The availability of experimental infrastructure for strength research at CIAM enables conducting comprehensive multi-disciplinary research, including high-level model calculations, unique mechanical tests, and physical studies of deformation and destruction specifics for various materials and engine components. The methods developed by CIAM researchers, available instruments and other equipment are also used for engine certification testing and other types of engine bench and flight tests, including those conducted by various companies in the industry. The results of strength tests conducted using CIAM's experimental infrastructure were used during refinement, certification, and enhancement of practically all USSR and Russian aircraft engines, as well as contractual work for foreign firms.

Special and Strength Certification Testing

The ever-increasing importance of engine strength and service life testing can be clearly illustrated by data from Rolls-Royce (M. Terrett. Civil Aerospace Briefing Presentation, June 18, 2003, Rolls-Royce). According to these data, the strength and service life testing accounted for about 10% of the total number of engine 3 tests in 1960, over 50% in 1970, and over 85% in 2000.

CIAM's equipment for strength certification testing is designed for the following:

- Fatigue testing of prototypes and components;

- Low-cycle fatigue testing, static crack testing, and fatigue crack growth testing;

- Static and cycle testing of materials and components under unsteady loading and triaxial duty cycle loading conditions;

- Long-time and short-time strength testing and creep testing of materials at temperatures of up to 1900 K in the air;

- Thermomechanical stress cycle testing of turbine blades and other turbine components with simulated thermal stress conditions in the component’s critical section;

- Cryogenic testing of materials;

- Testing of materials in a hydrogen environment under tension, twisting, and internal pressure loading conditions;

- X-ray diffraction and metallographic examinations and scanning electron microscopy;

- Analysis of metallic, ceramic, and composite material performance at high temperatures;

- Examination of mechanical properties of high-temperature materials under tension, compression, bending, and shear in various environments;

- Analysis of strength, life, and dynamic performance of rotor components; case damage containing ability analysis;

- Vibration refinement of rotors;

- Rolling bearing and gear testing;

- Bird strike and blade separation testing of rotating rotors (impellers).

CIAM's rigs for special certification testing can be used for safety testing of not only aircraft engines, but also structural aircraft components (wings, stabilizers, cockpits, etc.) and power plants under icing, bird strike, foreign matter ingestion, and open flame (fire) conditions.

Strength testing is conducted:

- To prove safe engine operation capability as part of engine certification;

- For calculation method verification;

- To prove engine strength reliability in conditions that can be difficult to simulate by calculation analysis;

- To create a structural strength data bank for materials;

- To verify and optimize new design and process solutions.

 The availability of experimental infrastructure for strength research at CIAM enables conducting comprehensive multi-disciplinary research, including high-level model calculations, unique mechanical tests, and physical studies of deformation and destruction specifics for various materials and engine components. The methods developed by CIAM researchers, available instruments and other equipment are also used for engine certification testing and other types of engine bench and flight tests, including those conducted by various companies in the industry. The results of strength tests conducted using CIAM's experimental infrastructure were used during refinement, certification, and enhancement of practically all USSR and Russian aircraft engines, as well as contractual work for foreign firms.

Studies of Physical and Chemical Properties and Operational Performance of Future Fuels and Lubricants

CIAM's test rigs for studies of physical and chemical properties and operational performance of future fuels, lubricants, and special fluids allow determining:

- Antiwear properties of aircraft fuel;

- Lubrication properties of aircraft GTE lubricants in gear systems;

- Tribotechnical characteristics in sliding friction conditions at temperatures of up to 1000 °C;

- Lubricant performance at specified loads and temperatures;

- Lubricating and antiwear properties of aircraft oils and greases;

- Fuel cooling capacity and capability, heat output, and cocking behavior, impact of various fuel additives on the level of thermal decomposition under high-temperature heating conditions;

- Combustion performance of standard and experimental jet fuels;

- Nature of aircraft GTE fuel impact on rubbers used in fuel heat exchangers and thiokol sealant;

- Thermal oxidation properties of aircraft GTE lubricants;

- Thermal oxidation properties of fuel.

Gas Dynamic and Thermal Physical Process Studies

CIAM's test rigs enable studies of gas dynamic and thermal physical processes taking place in aircraft engines:

- Studies of steady and unsteady flows in models of curved ducts of aircraft engines, in air intakes and nozzles; testing of fuel feed arms, fuel flow stabilizers, and injectors;

- Studies and development of acoustic performance improvement methods;

- Dynamic gas bearing studies;

- Heat exchange process studies. 

Studies of Physical and Chemical Process Kinetics

CIAM's laboratories allow conducting studies of fundamental physical and chemical processes in reacting gas flows and fuel combustion processes for future fuels.

Measuring Instruments and Metrological Competences

CIAM's researchers have developed a number of measuring instruments for special measurements used in experimental item testing at CIAM and aircraft engine designers' rigs, such as: pyrometric instruments, thermal paints, high temperature boroscope equipment for radial clearance measurements, and measuring instruments based on PIV and LDV equipment.

The State Measuring Instrumentation Test Center (SMITC) functioning on CIAM's base conducts tests necessary for measuring instrument type approvals, such as mechanical, pressure, temperature, flow rate, dynamic performance (vibration, deformation, pressure fluctuation, etc.) tests, relative humidity, airflow speed and direction tests, frequency, radiotechnical and radio electronic tests, electrical tests, etc.