Aerospace Science & Technology

SARAS

NAL’s Light Transport Aircraft - SARAS - has completed a significant milestone of rollout just before the year commenced. During the year, preparations for its first flight were launched and a large number of ground tests were performed on the aircraft. These includes structural tests on full scale airframe, engine integration and running tests, instrumentation checks, tests on avionics and electronics systems and ground vibration tests. In addition a large number of materials’ characterisation and other tests were conducted to satisfy the certification requirements. Extensive reviews have been completed. All these have resulted in Director General of Civil Aviation (DGCA) giving clearance to the flight trials of the aircraft. Low speed taxi trials are about to be commenced and these will be followed by high-speed taxi trials, analysis and discussion of the results with DGCA before the first flight.

Hardware for mesoscale modeling for monsoon related predictions developed

NAL has designed and developed Optical Floswitch - the hardware component of the Mesoscale Modeling for monsoon related predictions. NAL Floswitch has the decisive edge on the connectivity, bandwidth and information processing capability and is technically superior to the commercially available systems anywhere in the world. On the modeling front, components of modeling, which have been developed and integrated, specially address to the tropical region. It will, thus reduce, to a large extent, the dependencies on western models and consequently increase reliability in forecast for tropical regions.

Improved software for Pressure Sensitive Paint (PSP) data processing

PSP technique involves the use of pressure sensitive paints for the measurement of surface pressure distributions on wind tunnel models. This method has a great advantage of no pressure probe intruder into the flow. The PSP data reduction process which transforms intensity data in the image plane to pressure data mapped to spatial coordinates of the model is an important element in the accurate determination of surface pressure on the wind tunnel model.

Keeping in view the futuristic requirements, NAL has developed a state-of-the-art PC-Windows based software. It has some excellent features like, automatic marker recognition, conventional methods of image alignment using warping transformations and image transformation using resection methodology onto a three-dimensional surface grid on the model. NAL scientists have validated the software against data and conventional pressure measurements on an aircraft model in a 1.2m wind tunnel and at transonic speeds at NAL.

Pressure coefficient data on aircraft using resection method

Shape Memory Alloys (SMAs) developed for aerospace applications

Ni-Ti based Shape Memory Alloys (SMAs) emerged as very promising material for aerospace applications. Some of the applications envisaged are active and adaptive in shape control in aerospace structures and various actuator applications. All these applications require SMAs in the form of wire with a range of transformation temperatures and mechanical properties. NAL has achieved capabilities for processing of Ni-Ti based actuator wires and springs from SMAs.

SMA Spring fabricated at NAL

Civil aircraft avionics and stall warning systems

NAL has successfully developed avionics systems and electrical systems for SARAS aircraft to meet international airworthiness specifications. Necessary bench level test facilities and test methodologies are also established and proven. The systems developed have been tested using these facilities and also on aircraft tests. Application software for certain systems procured on a semi-knocked down basis have been developed and tested. A critical input on aircraft pilot is generated by the stall warning system, which warns about the aircraft’s likelihood of entering into stall. NAL has also developed indigenous software for this system. All these have formed valuable inputs to the country’s civil aviation programme in general and SARAS aircraft in particular.

SARAS Stall Warning System

Cure controller for bonded repair developed

Cure controller is electronic equipment used for in-situ bonded repair of aircraft structures. Both metallic and composite structures can be repaired using this equipment. NAL has designed and developed two versions of cure controllers. One is a microprocessor-based system capable of single zone control and the other is a notebook PC based system capable of multizone control. This system is the first of its kind in the country and provides an essential tool for onsite, in-situ repairs. Being portable they are useful in a variety of industrial situations but the most important of these is repair of aircraft structures in the operational bases.

Radomes

Over the years the multi-disciplinary radome activity has become a strength area of NAL. During the year NAL successfully completed development and production of nose radomes for Jaguar Maritime aircraft using resin injection technology, which is an in-house development. The radomes have successfully passed through the acceptance criteria and preliminary flight trials are in progress.

NAL has also developed ceramic radomes for strategic applications and handed over prototype radomes to DRDL (DRDO Laboratory) for field trials.

In the area of ground based radome, the process for development of large panels for second version of the Doppler Weather Radome (DWR-Mark II) has been successfully demonstrated.

Acoustic test facility

NAL has conducted detailed qualification tests of many space systems during the year using the Acoustic test facility. The significant systems tested included two major flight hardware systems of GSLV and 2 satellites (IRS Pt and INSAT 3E). This facility is unique in the country and there are a few in the world, which are capable of meeting the space specific test standards. NAL’s contributions in this discipline are both unique and invaluable.

The Acoustic Test Facility has also developed gas jet noise generator whose performance is excellent and covers a range of operations, which is not covered by any other system anywhere in the whole world so far. This first-in-the world type system has been supplied to prestigious aerospace companies including Boeing, USA and has received wide recognition.

INSAT-3-E in Acoustic Test Facility
Noise Generator

Automatic visual range assessor installed at Cochin

The visual range is a parameter of central importance in flight operations, which determines whether a pilot may land, or take-off. Over estimation assessments of visual range violate safety guidelines. On the other hand, heavy financial losses and inconvenience would be incurred by delays and diversions created by under assessments of visual range. To meet the need for timely yet accurate reports, NAL has designed and developed the Automatic Visual Range Assessor (AVRA). The AVRA automatically assesses and reports visual range at 10-second intervals. The system has met the acceptability criteria successfully

The Category 2 variant viz., the AVRA Mk2S, has been installed at Cochin International Airport in December 2003. This is a single baseline system that assesses and reports the Runway Visual Range (RVR) between 200m and 3300 m and the Meteorological Optical Range (MOR) between 200 m and 10000 m. The unit has been functioning satisfactorily for the last four months.

Automatic Visual Range Assessor at Cochin Airport

1.1.2 HUMAN RESOURCE DEVELOPMENT

  • A workshop on "Structural Dynamic Simulation and Testing - a Hybrid Approach" was organized at NAL between 10th and 12th March 2004 jointly by NAL and LMS International, Belgium. The workshop covered a variety of latest topics on the use of "virtual engineering" technology in aircraft design. Dr A R Upadhya, Associate Programme Director, Aeronautical Development Agency (ADA) and Programme Director, National Programme of Smart Materials made a presentation on 'Structural Dynamic Simulation and Testing of Aircraft' illustrating the ongoing testing and simulation studies on the Tejas- Light Combat Aircraft (LCA).
  • Series of lectures were delivered by experts from General Aerospace Research Centre (DLR), Germany on the area of Flight Mechanics in March 2004.
  • An Official Language Orientation Programme for NAL’s Heads of Divisions was organised in March 2004. The training aimed at increase in use of official language at senior levels.
  • Periodic orientation courses were conducted for fresh entrants to familiarise them with NAL’s programmes and activities.
  • Specially designed courses aimed at upgradation of PC Awareness among staff members were also conducted during the year.
  • Under a special arrangement with Birla Institute of Technology & Science, Pilani a batch of their final year students participated in NAL programmes
  • About 800 students of Engineering from different universities did their dissertation projects in NAL.
  • Over 400 staff members were deputed to about 110 specialised Conferences / Symposia / Workshop to enable exposure and upgradation of their knowledge base.

1.1.3 RECOGNITION & AWARDS

Padmashri Dr. T.S. Prahlad, Distinguished Scientist & Ex Director, NAL
CSIR Technology Shield for Engineering Technology for integrated flight mechanics and control technology for aerospace vehicle Dr. J.R. Raol & team, NAL
Young Scientist Award by Indian National Academy of Engineers Dr. A.A. Pashilkar, NAL
MRSI Medal 2003 by Material Research Society of India Dr. R. M.V.G.K. Rao, NAL
National Prize in aeronautics by Aeronautical Society of India Mr. Subbarao, NAL
Mrs. Sabita Chaudhury Memorial Medal of Indian Institute of Science (2001-02) Dr. A.A. Pashilkar, NAL