Aerospace’s new age alloy- Aluminum Lithium

In aerospace industry, it’s clear that weight is a variable everyone want to drive down.

And most efforts in this regards goes to getting newer materials and alloys.

In this light, I am following development of aluminum lithium.

A couple of days back one of my favorite aviation blog had a post on this very material. You can read the full post here.

Here’s an extract on aluminum lithium alloys from the post.

  • Lower the weight of an airplane by up to 10% vs. composite-intensive planes;
  • Lower the cost to manufacture, operate and repair planes by up to 30% vs. composite-intensive planes, and at significantly lower production risk;
  • Allow for a 12% increase in fuel efficiency, on top of the 15% from new engines; and deliver passenger comfort features equivalent to composite-intensive planes, such as higher cabin pressure, large windows and higher humidity.
  • If you are interested in this aluminum alloy which is increasing seeing uses in aircraft including the Rafale and space shuttle external tanks, read this PDF report.

    And if you are interested in a short history of composites in civil aircraft then click the link below.

    History of Composites in civil aircraft [PDF]

    The Birth of Rafale – Integrated Design of Advanced Fighters Lecture

    BirthOfRafale Although so many days have past since Dassault Rafale has tentatively won MMRCA, the mother of all tenders.  And ever since my twitter and Google reader feed is overwhelmed by reports and news on Rafale and Typhoon. Constantly reading so many posts,reports and analysis on this.

    Today morning when nothing new turned up, I headed to Google. And Google led me to this pdf from the year 1987.

    The pdf contains a lecture by Jean-Claude Hironde, Rafale program manager on design optimization for a family of multi role combat aircraft.

    Rafale plays as the central protagonist in this fascinating report. The technical report uses design of multi-role combat aircraft design process as an example throughout the lecture.

    It’s essentially a technical talk about the conception of Rafale, gives you an insight on what were the various design decisions made by the engineers when Rafale was still on paper. Fascinating stuff, if you don’t mind the rough, illegible  scanning job.

    Must weekend read if you are interested in combat aircrafts!!

    The Birth of Rafale [pdf]

    Rafale wins MMRCA

    I was rooting for Typhoon, but the French’s Rafale wins the 10 billion dollar mmrca deal.

    A total of 126 Rafales will be supplied to the IAF in the next 10 Years, of which Dassault aviation will supply the initial batch of 18 Aircrafts and the remaining will be manufactured at HAL, India.

    As many believe, Typhoon offers superior air-to-air capabilities, the Rafale is truly multi-role and better in the air-to-surface role.

    So finally IAF will grow out it’s MIG’s and Russian fighters.

    rafale India aero show

    MMRCA-Typhoon leads the race -Telegraph

    RAF Typhoon leads the race to secure £7bn arms deal – Telegraph http://t.co/YzxtWGNI

    The above report suggests that purely on technical terms, Eurofigher is ahead in MMRCA race.

    “There are a number of cost and strategic considerations which still have to be looked at, but in purely technical terms, Eurofighter is ahead,”

    The Eurofighter is more expensive than its competitors in upfront costs but the Typhoon consortium is confidant that it will be cheaper than it’s competitors over the life of it’s deployment.

    The report adds “Winning the contract would be a jobs boost not just for BAE Systems’ Warton plant in Lancashire but also the Rolls-Royce factory in Bristol, where its EuroJet 200 engines are built. It would also benefit 300 small and medium enterprises throughout Britain.”

    The fighters of MMRCA- Typhoon & Rafale

    MMRCA Typhoon vs Rafale

    Ministry of defence is to open bids for medium range multi-role combat aircraft (MMRCA) contract on 4th November. Every eyes on the two fighters who will be battling it out for the lucrative contract of 126+ fighter planes from Indian army.

    Eurofighter consortium has Typhoon, while French firm Dassault has Rafale.

    Its the classic French Vs English fight and will be fought on little details.

    Typhoon is powered by EJ200 gas turbine engine and Rafale with M88-2.

    Here’s a head to head comparison between the two power plants.

     

      M88-2 EJ200
    Thrust(lb) with afterburner 17000 20000
    SFC with afterburner (kg/daN.h) 1.7 1.76
    Dry SFC (kg/daN.h) 0.8 0.83
    Air Flow (kg/s) 65 77
    Turbine Inlet Temperature (K) 1850 1800
    Pressure Ratio 24.5 26
    By pass Ratio 0.3 0.4
    Thrust to Weight (afterburner) 8.5 9.175
    Length (in) 139 157
    Inlet Dia (in) 27.5 29
    Weight (lb) 1977.5 2180
    Low Pressure Compressor 3 3
    High Pressure Compressor 6 5
    High Pressure Turbine 1 1
    Low Pressure Turbine 1 1

     

    Component wise, EJ200 has the advantage of lower HP compressor stages. But Ej200 is longer and heavier than M88-2.

    Thrust wise EJ200 has more bang than M88-2. M88-2 beats Typhoon at fuel consumption.

    M88-2 operates at higher turbine inlet temperature meaning less turbine life.

    Each of this engine has their own advantage and disadvantage.  But ultimately the decision might be based on the offset than the technical.

    All I can say is may the best Fighter win!!

    Don’t forget to watch this Eurofighter Typhoon Vs Dassault video.

     

    And Don’t forget to check the interesting discussion going on here

     

    What’s your views?

     

    Sources:

    http://typhoon.starstreak.net/Eurofighter/engines.html
    http://en.wikipedia.org/wiki/Snecma_M88
    http://en.wikipedia.org/wiki/Eurojet_EJ200