Tu-160 "White Swan"

kvs wrote:Pretty acceptable?   Two years is miraculous.   Even China with all its massive resources couldn't pull something off like this.  
As for the USA, it is hard to tell what engine innovation they actually have.   I do not think they evenhave an NK-32 class engine.  
The GE F101 is basically half of the NK-32.   Given the rot in the US MIC, it would take more than 2 years for even just an
improved version of GE F101 to be put into service.   And that is without losing the production infrastructure.
...

lancelot wrote:

kvs wrote:Pretty acceptable?   Two years is miraculous.   Even China with all its massive resources couldn't pull something off like this.  
As for the USA, it is hard to tell what engine innovation they actually have.   I do not think they evenhave an NK-32 class engine.  
The GE F101 is basically half of the NK-32.   Given the rot in the US MIC, it would take more than 2 years for even just an
improved version of GE F101 to be put into service.   And that is without losing the production infrastructure.
...

You are correct. They do not. But the US does have civilian subsonic engines of that weight class (think 787 engines) and larger (think 777X engines).
They can "simply" use that engine core and militarize it. It won't be as hard as designing a new engine but it won't be as difficult either.
A Boeing 787 engine has between 28 and 34 ton thrust. A Boeing 777X engine has 48 ton thrust.

For reference the PD-35 will have 35 ton thrust. So that puts it roughly in the Boeing 787/Airbus A330 class.
The PD-35 (35 ton) is going to be a new engine based on a scaled up PD-14 (14 ton) core. Not based on NK-32 at all.
There was talk about using the NK-32 on the CRAIC 929 instead of PD-35.
But PD-35 should have better performance since it is more modern design.
It will use a lot of new technologies for Russian engines including carbon composite cold fan blades and SiC (ceramic) hot section parts.

GarryB wrote:
To operate at mach 4.2 it wont be using a turbofan or turbojet engine except for takeoff and landing... the rotational speed needed to operate at such flight speeds would destroy any conventional turbojet or turbofan engines... it would be like using rubber tires on a motor bike that can travel at mach 1.5... at that rotational speed the rubber would disintegrate causing the bike to crash... the turbine blades in a conventional jet engine can't operate above about mach 2.8 without damage.

mnztr wrote:
Rotational speed is not directly related to speed of the plane. To get to M 4.2 what you need is exhaust velocity, i.e the exhaust has to exceed M 4.2 and have enough mass to power the plane at that speed. Sure this will be one tricky thing to manage. Its possible a new intake and  exhaust nozzle can be designed with more air bypassing the engine intake and being combined in an afterburner plenium to increase thrust and efficiency of the afterburner. (it would work like a quasi ramjet) exiting thorugh a variable exhaust the exhaust velocity will have to be managed electronically so the engine does not surge. SR-71 used similar ideas. The Mig-25 took a different apporach, it had very low compression ratio, and actually depended on airspeed to increase the effective compression ratio. As a result it was very inefficient at low speed. As the plane speeded up to critical speeds the compressor would become unloaded and could over speed. As well engine temps would skyrocket from compression heating as the effective compression ratio kept rising. You are right that turbines cannot handle supersonic airflows, so the intake can use ramps to reduce the intake volume at speed, or in the case of SR-71 or what I suggest, simply redirect this partially away from the turbine intake and operate like a ramjet.

GarryB wrote:

Instead, building whole new planes is beneficial for multitude of reasons:
- re opens production which was lost initially. Meaning more jobs and specialists
- gives opportunity to re-tool the plant
- bigger order and thus more money to plant.
- gives opportunity to seek improvements to the plane in the airframe/structure (more composites)
- with newly trained specialists, means better opportunity to have a new design and properly working plane in future.

It creates production of parts and systems in Russia that used to be based in the Ukraine and other former Soviet States... most of which is still based on Soviet era technology and materials and has not been dramatically upgraded.

New Russian makers can use new technology and design and production techniques etc etc to make it new generation like they have with other items they are producing now with all improved and upgraded components in upgraded tanks and upgraded ships etc but also new designed from scratch tanks and ships etc.

It means production will take place in brand new Russian factories who can use the new equipment and tooling for other new projects as well with all the money invested invested in a Russian company rather than one located in a different country... with the added bonus of payments in Rubles and no money wasted on currency trading.

The plant can be scaled to need rather than what the Ukrainians want.

All new generation tools and materials and design techniques can be applied on these replacement engines and aircraft etc etc to get maximum performance improvement.

Everything is located in Russia so when it comes to export potential they have the say because they own the design and can control production and dont need permission and are essentially sanction proof.

It also allows them to compete on the open market in competition with their former suppliers which means potential contracts to support Soviet aircraft in other countries with components that will be related to the new systems in their new products... ie they can provide engines to replace those currently used in their own aircraft that used to be Ukrainian but are also making new engines for new aircraft... both of which they can sell to replace older obsolete Soviet types.

Rotational speed is not directly related to speed of the plane.

Of course it is... the two ways to increase airflow through a jet engine is to increase the shaft spin rate or change the angle of the blades on that shaft.... and I am not aware of any jet engines that have variable angle blades all the way through them.

To get to M 4.2 what you need is exhaust velocity, i.e the exhaust has to exceed M 4.2 and have enough mass to power the plane at that speed. Sure this will be one tricky thing to manage.

it is trickier than that... they need to slow the velocity of the air going into the engine to subsonic speeds so the fuel can burn in the hot section and then expel the air out the rear of the engine at high speeds to get the thrust needed to move the entire aircraft at that flight speed.

Being a turbofan a bulk volume of air does not go through the hot section, but even then the top flight speed of the MiG-25 is about Mach 2.84 for about 5 minutes and then you need to slow down.

As you mention the SR-71 does not run its engines at more than idle speed when flying very fast... it is all bypass ramjet propulsion.

In both cases it is because the rotational speed needed to achieve flight speed without ramjet tricks will destroy the blades and the engines.

PhSt wrote:Source: the first Tu-160M ​​built from scratch will take off in the IV quarter of 2021

MOSCOW, December 30. / TASS /. The first prototype of the deeply modernized strategic missile carrier Tu-160M ​​of the new construction will take off in the 4th quarter of 2021. This was announced on Wednesday by a TASS source in the military-industrial complex.

"Next year - a new assembly," - said the agency's interlocutor, answering a question about the progress of work on the Tu-160M.

According to him, the completely new Tu-160M ​​will take to the air "most likely in the 4th quarter of 2021."

The second prototype of the Tu-160M ​​is undergoing ground tests at the flight test station of the Kazan aircraft plant named after V.I. SP Gorbunova, a source told TASS. "The second [car] at the exit, they are already working out, in the shop ... at the flight test station," the agency's source said, adding that this machine was also made on the basis of the previously built Tu-160, "the agency's source said.

In early November 2020, the deeply modernized strategic missile carrier Tu-160M ​​made its first flight with new NK-32-02 engines from the airfield of the Kazan aircraft plant named after V. S.P. Gorbunova. According to the UAC, the flight tested the updated general aircraft systems and avionics installed during the aircraft modernization, as well as the performance of the new NK-32 02 series engine.

Tu-160 is a multi-mode supersonic strategic missile carrier with variable wing geometry. In 2015, it became known about the decision to resume production of the Tu-160 in a modernized version of the Tu-160M. On February 2, the first experienced deeply modernized Tu-160M ​​"Igor Sikorsky", created on the basis of the combatant Tu-160, took to the air for the first time. He received new flight and navigation equipment, an on-board communications complex, a control system, a radar station, and an electronic countermeasures complex.

TMA1 wrote:hey is the new built tu-160 getting a new canopy as well??

PapaDragon wrote:

TMA1 wrote:hey is the new built tu-160 getting a new canopy as well??

Highly unlikely

They never change what works and fuselage on Tu-160 works like a charm