Requiem

Babam 12 Aralık 1941’de Denizli’nin Tavas ilçesine bağlı Kızılcabölük kasabasında dünyaya geldi. Doğum günü sorulduğunda ses tonu hafif değişir gururlanarak oniki oniki bin dokuzyüz kırk bir derdi. Ne kadar da kolay akılda kalıcak bir doğum tarihim var der gibi söylerdi bunu. Nüfusa kayıtlı adı Mehmet Talât’tır. Ancak hayatı boyunca iki isimli olmanın çok sorun yarattığını fark edip herkese çocuklarına tek isim vermelerini tavsiye ederdi. Kızına Nevra ve oğluna da İbrahim ismini verdi. Torunun da tek ismi vardır Defne.

2016 yılı sonunda doktor muayenesinden eve geldiğinde hastalığının teşhis edildiğini ve ünlü profesörünki (Stephen Hawking) gibi ALS olduğunu sanki grip teşhisi konmuş gibi gülümseyerek söylediğini unutmuyorum. Çocukluğumda zatüre olduğumu öğrendiğimde annemlerin yatağına gidip ağladığımmı hatırlıyorum. Çok güçlü bir kişiliği vardı babamın.

Doğup büyüdüğü çevrenin çok ötesinde bir bakış açısına sahipti. Bu bakış açısı ona hem işinde hem de ailesinde başarı ve mutluluğu getirdi. Yabancı dil öğrenmenin önemini erken yaşta farkedip iki çocuğunu da Amerikan kolejinde okuttu. Babamın geniş bakış açısına layık olarak onu farklı dillerde anlatmak istedim. Kitabını da tüm dünyada satış yapan bir firma üzerinden yayınlıyorum.

Baba seni çok seviyorum, ve özlüyorum.

30 Ekim 2025, İstanbul, Türkiye

İbrahim Kocaalioğlu

Hybrid Turbofan Engine

Turbofan engines are the critical bottle neck of the aircraft designs. Lack of high thrust turbofan engines limit the payload capacity of the planes. Adding more engines is not the ideal solution. I would like to propose a hybrid high bypass turbofan engine especially for high thrust applications. The idea is to generate high thrust using already availably rocket engines and power the turbofan using the exhaust of the turbopumps of the rocket engine.

The design requires compacted rocket engines to be split into sections and modified to be adapted as a high bypass engine. Unlike air breathing turbofan engines, the hybrid engine I propose will consume liquid oxygen instead of relying on ambient air. However, large turbofan section will suck large volumes of air and increase the amount of accelerated exhaust gas. This will increase the ISP of the engine compared to a rocket engine. The turbofan will be driven by the exhaust gas of the rocket turbopumps.

Main drawback of the engine is its reduced fuel efficiency compared to traditional engines. However, designing and manufacturing very high thrust turbofans are prohibitively expensive and complex.

On the other hand, the advantages of the hybrid engine I propose are:

- They rely on already mass-produced high thrust rocket engines.

- They don’t require ambient oxygen to operate. Which increases their service ceiling.

- They can operate with liquified methane. Which is much greener than jet fuels.

If the future of aviation is hydrogen, liquid methane consuming hybrid turbofan engine would be the next step.

Hybrid Staged Rocket

Aerospace refers to the technology and industry involved with the atmosphere and outer space collectively. However, the collaboration between the aircraft and spacecraft design is below par. I would like to propose a hybrid staged rocket design. Where each stage can be reconfigured for different projects on demand.

The aircraft section of the hybrid rocket will be composed of two stages. The first stage will be powered by highly efficient high bypass turbofan engines. The delta wings will generate lift and are structurally sturdy. This is important while the wings need to lift heavy weight of the upper stages. Due to lift generated by the wings, the turbofans do not need to generate the thrust of a classical rocket’s first stage. The objective of this stage is to ascent the upper stages to the commercial aviation altitudes and speeds. Once the objective is reached and most of the fuel is consumed, the upper stages are separated. The first stage than flies back to the launch airport. This is a much simpler engineering problem compared to returning a rocket’s first stage to the launch site.

The second stage of the hybrid rocket will be a smaller delta wing with convertible ramjet engines. The engines will be fired close to Mach one during stage separation. The engines will operate in ramjet mode until Mach 4 and then they will transition to a scramjet above that speed. Unlike traditional rocket first stages, this stage will reach high speeds at lower altitudes due to air breathing nature of the engines. Once, most of the stage fuel is consumed, it will separate from the upper stages. Like the first stage, the second stage will also fly back to the launch site. Due to engines inefficiency at lower speeds, this will require more fuel. The delta wings will allow passive deceleration with improved stability.

The remaining upper stages of the rocket will have classical rocket design. They will be called high-altitude, high-speed rockets unlike the traditional ones that are launched from the ground with zero initial speed.

The first two stages of the hybrid rocket will also be used at high-speed, high-altitude testing of rockets (civil and military) and aircrafts. At the moment aircrafts with classical framing are used for this task and they are not optimal for the task.

Gotham Orbit

I would like to call the Low Earth Orbit as Gotham Orbit. As more companies deploy more and more satellites into this orbit, the crime rate in the orbit will inevitably increase like in Gotham City. Space junk poses high risks to the citizens of the orbit, cube sats earth observation and communication sats… like the air pollution of a metropolitan city. Even though there is no officially declared crime committing satellites in the orbit, most probably there are ones already. Once they are recognized I would like to call them the Joker satellites. Like the fictional Joker character, these satellites would paralyze their victim satellites by many ingenuous ways.

The question is will we have super hero satellites to protect our vulnerable space infrastructure from the crimes of space and what SuperSat abilities these satellites will have?

The article was written in Adana after my father.