Skip to main content

Posts

Showing posts from January, 2021

1.1 How Aircraft Design Developed:AAD1

Lets take a minute and reflect on the aviation industry.  Like every other industry, there is a boom of new design, new product, new services in the initial phase of the industry, where all the companies try to understand the market need and provide a solution to this. They give out different designs and configurations. After the market has been mature enought, there come a handfull of products which are more favoured. The reasons may be that the product was more comfortable, cheaper, easier to handle, easier to maintain and so on. However, there comes a point where the industry is lead by a particular product and other companies follow suit. And the market focuses on this particular product and product improvement is the next phase.  So this is the analogy that i want to make with aircraft. Roughly speaking much of the advancement we see in the field of aviation up until the mid 20th century is because of war. The aircraft needed to be better, faster and more efficient. The u...

1.1 Introduction: Configuration Aerodynamic: KA

 So what are the important things to consider while defining the configuration of aircraft.  What are the important aspects of configuration concept? 1. Wing design.  2. Payload accomodation. 3. selection and arrangement of propulsive system 4. Arrangement of lift generating surfaces 5. Arrangement of control surfaces 6. placement of undercarriage. Also there should be a way to test all this improvements that we promish with better configurations. This can be done with DOC- Direct Operating Cost. This is of two variant for civil aircraft.  1. DOC for passanger aircraft. cost /(Eb *np)= €/km/pax 2. DOC for cargo aircraft. cost / (Eb* mp)=€/km/kg Eb= range*nf nf= total number of flights range= the range of the flight  mp= mass of payload np= number of passanger For the Range we should know the formula. the more popular formula for the range is Breguet Formula, which is: R= 1/(SFC*g)*v*Ca/Cd*ln(Wstart/Wend) where the formula composes of 3 different parts 1. Aerodyn...

1.0 Introduction: configuration aerodynamics:KA

Before we start the design of aircraft there are couple of things that needs to be clear. For any design to take place there should be a clear defination of requirement. This is called High level requirements. The range of the aircraft, payload, the operation condition, the cruise speed.  Important questions:  A. What are the operational Requirements? 1. Payload- size, type and weight 2. Range- long range or short range 3. Mach Number- design Mach Nr. ie cruise speed 4. Runway requirements- length and texture of runway 5. Mission requirements- longer distance flight or more maneuverability more important 6. Operation cost B. What are the safety and legal requirements? 1. Start and landing distance 2. Noise restriction 3. Staggering distance during takeoff and landing 4. Performance requirement for engine failure.  There two requirements are with different perspective. the second is only concentrated on the safety of the operation.  Here i would like to specifically f...