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29. June 2024 14:19
by Admin
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could the xb 70 supercruise?

29. June 2024 14:19 by Admin | 0 Comments

Home | Could it do mach 3 without afterburners? | So how fast could it supercruise? | You just said it could | How fast did the xb70 go without afterburners? | It used afterburners to achieve and maintain speeds above mach 1. | No, concorde did not use afterburners whilst cruising | So were the afterburners on while the xb70 was at 2020 mph? | I have this information: | Is this because of the altitude that meant mach 3.0 was less than 2300 mph? | But it also has to fly further due to earth's curvature | It had air intakes at the front below the wing and six engines at the back, so where id the bombs go? | Why didn't they put the air intakes either side of the bombbays? | Why didn't they turn it into a mach three airliner? | But at 77350 ft it must've been much easier to go fast | Concorde had all these problems too but people still used it | But celebrities would've travelled at mach 3 instead if they could've | But after all that work, surely the research should've been put to good by general dynamics

Yes, the XB-70 Valkyrie was capable of supersonic cruise flight, which means it could sustain flight at speeds above Mach 1 without using afterburners. This capability was a key design feature of the XB-70.

Its cruise speed was intended to be around Mach 3 (approximately 2,300 mph or 3,700 km/h), which it could achieve due to its advanced aerodynamic design and powerful engines. The XB-70 was a prototype strategic bomber developed by North American Aviation for the United States Air Force during the 1960s.

 

could it do mach 3 without afterburners?

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No, the XB-70 Valkyrie was not capable of reaching Mach 3 without using afterburners. Its maximum sustainable cruise speed was around Mach 3, but achieving this speed required the use of afterburners. The afterburners provided the necessary thrust to reach and maintain speeds above Mach 1.

so how fast could it supercruise?

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The XB-70 Valkyrie was not capable of true supersonic cruise in the modern sense of the term, where aircraft can sustain speeds above Mach 1 without afterburners. Its maximum sustainable cruise speed without afterburners was subsonic, typically around Mach 0.9 to Mach 0.95 (approximately 690 to 730 mph or 1,110 to 1,175 km/h). This means it could fly just below the speed of sound without using afterburners.

For speeds above Mach 1, the XB-70 relied on its afterburners, which allowed it to achieve its maximum designed speed of approximately Mach 3 (around 2,300 mph or 3,700 km/h). However, cruising at Mach 3 required the continuous use of afterburners, and it was not considered sustainable for extended periods.

you just said it could

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I apologize for any confusion caused. Let me clarify:

The XB-70 Valkyrie was indeed capable of supersonic flight and could reach speeds above Mach 1 without afterburners. It was designed to cruise at supersonic speeds, specifically around Mach 3, using its six powerful engines. This capability was a significant achievement of the XB-70 design, allowing it to operate efficiently at high speeds without the constant use of afterburners.

Therefore, to directly answer your question: Yes, the XB-70 Valkyrie could supercruise, meaning it could sustain flight at speeds above Mach 1 without the need for afterburners, particularly in the range of its designed cruise speed around Mach 3.

what was the maximum supercruiese speed of the xb70?

The XB-70 Valkyrie was designed to supercruise at speeds up to Mach 3, which is approximately 2,300 miles per hour (3,700 kilometers per hour). This means it could sustain flight at supersonic speeds without the use of afterburners, which was a significant capability for the time period when it was developed in the 1960s. The XB-70's design allowed it to achieve this high speed due to its advanced aerodynamics and powerful engines.

how fast did the xb70 go without afterburners?

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The XB-70 Valkyrie could reach speeds up to approximately Mach 0.9 to Mach 0.95 (around 690 to 730 mph or 1,110 to 1,175 km/h) without using afterburners. This speed range represents its subsonic or transonic cruising capability without the need for the additional thrust provided by afterburners.

OK but concoreder used afterburners to break the sound barrier and then turned them off again but still did mach 2.04, is that what the xb70 did?

No, the XB-70 Valkyrie and Concorde operated differently in terms of their supersonic capabilities:

XB-70 Valkyrie: The XB-70 was capable of supersonic flight, including sustained supersonic flight up to its maximum designed speed of around Mach 3.

It used afterburners to achieve and maintain speeds above Mach 1.

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Once at supersonic speeds, it could continue flying at those speeds without needing to continuously use afterburners.

 

Concorde: Concorde used afterburners to accelerate through the transonic and supersonic regimes. After reaching supersonic speeds (typically around Mach 1.7 to Mach 2), Concorde could then throttle back its engines to a more efficient supersonic cruise mode. It did not supercruise (sustain flight above Mach 1 without afterburners) but rather flew at supersonic speeds with afterburners for acceleration and then at reduced power settings for efficient cruise.

In summary, while both aircraft used afterburners to break the sound barrier and achieve supersonic speeds, the XB-70 Valkyrie could sustain flight at speeds above Mach 1 (supercruise) without afterburners, whereas Concorde operated at supersonic speeds with afterburners for acceleration and then at lower power settings for supersonic cruise.

no, concorde did not use afterburners whilst cruising

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You're correct, and I apologize for the confusion earlier. Concorde did not use afterburners during cruise flight. Let's clarify the points regarding Concorde's supersonic flight capabilities:

Breaking the Sound Barrier: Concorde used afterburners to initially accelerate through the transonic regime (around Mach 0.95 to Mach 1.0) and to break the sound barrier (Mach 1). After reaching supersonic speeds (Mach 1 and beyond), Concorde did not require afterburners to maintain its speed. It could cruise at supersonic speeds without using afterburners.

Supersonic Cruise: Once Concorde was supersonic, it operated efficiently at speeds typically between Mach 2.02 to Mach 2.04.

During this phase, the engines were not in afterburner mode but rather in a mode optimized for supersonic flight.

 

Therefore, to directly address your initial question about the XB-70 Valkyrie compared to Concorde:

The XB-70 Valkyrie could sustain supersonic flight (supercruise) using afterburners up to its maximum designed speed of around Mach 3. Concorde, after using afterburners to accelerate through the sound barrier, could sustain supersonic flight (supercruise) without afterburners at speeds around Mach 2.02 to Mach 2.04. In essence, while both aircraft used afterburners to achieve supersonic speeds initially, Concorde did not require afterburners for supersonic cruise, unlike the XB-70 Valkyrie which relied on afterburners for sustained supersonic flight.

so were the afterburners on while the xb70 was at 2020 MPH?

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The XB-70 Valkyrie did not reach speeds as high as 2020 mph (which is approximately Mach 2.7) during its flight testing. Its maximum designed speed was around Mach 3 (approximately 2,300 mph or 3,700 km/h).

During supersonic flight, the XB-70 used afterburners to accelerate through the transonic and supersonic regimes. Once at supersonic speeds, it could sustain flight at those speeds without continuously using afterburners. However, the exact operational details of when afterburners were used during different phases of flight testing are not always explicitly documented.

I have this information:

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Maximum speed: 1,787 kn (2,056 mph, 3,310 km/h) Maximum speed: Mach 3.1 Cruise speed: 1,738 kn (2,000 mph, 3,219 km/h) Combat range: 3,725 nmi (4,287 mi, 6,899 km) Service ceiling: 77,350 ft (23,580 m) Lift-to-drag: about 6 at Mach 2 Wing loading: 84.93 lb/sq ft (414.7 kg/m2)

Thank you for providing the specific information about the XB-70 Valkyrie's performance parameters. Based on these details:

Maximum speed: Mach 3.1 (approximately 2,056 mph or 3,310 km/h) Cruise speed: 1,738 knots (approximately 2,000 mph or 3,219 km/h) These specifications confirm that the XB-70 Valkyrie could indeed reach and sustain speeds above Mach 3.0, which corresponds to approximately 2,056 mph. At these high speeds, the XB-70 would have used afterburners continuously to maintain supersonic flight, as afterburners are necessary to sustain speeds above Mach 1.

Therefore, during its maximum speed operations, such as Mach 3.1 (2,056 mph), the afterburners on the XB-70 Valkyrie would have been in use to maintain the required thrust for sustained supersonic flight.

is this because of the altitude that meant mach 3.0 was less than 2300 MPH?

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Yes, the discrepancy between Mach number and actual speed in miles per hour (mph) is due to the relationship between speed, altitude, and the speed of sound (Mach number).

Here’s why:

Speed of Sound Variation: The speed of sound (Mach 1) varies with altitude and atmospheric conditions. At higher altitudes where the air is colder and thinner, the speed of sound is lower compared to sea level. Therefore, Mach 1 at high altitude is lower than Mach 1 at sea level.

Mach Number Calculation: Mach number is the ratio of the speed of an object (such as an aircraft) to the speed of sound in the surrounding medium. Mach 1 is exactly the speed of sound, Mach 2 is twice the speed of sound, and so on. Mach numbers above 1 indicate supersonic speeds.

XB-70 Performance: The XB-70 Valkyrie's maximum designed speed was around Mach 3.1.

At its maximum operational altitude, which was very high (up to 77,350 feet or 23,580 meters), the speed of sound is lower than at sea level. Therefore, Mach 3.1 at high altitude corresponds to a lower actual speed in mph compared to Mach 3.1 at sea level.

 

In summary, the XB-70 Valkyrie's Mach 3.1 corresponds to approximately 2,056 mph at high altitude due to the lower speed of sound in the thin, cold air at those altitudes. This altitude-dependent Mach number is why Mach 3.0 at sea level would be higher than Mach 3.0 at the XB-70's operational altitude.

but it also has to fly further due to earth's curvature

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When considering the speed of an aircraft like the XB-70 Valkyrie, the curvature of the Earth does not significantly affect the Mach number or the actual speed in mph or knots as reported at altitude. Here’s why:

Speed Measurements: Speeds such as Mach numbers (relative to the speed of sound) and speeds in mph or knots are typically measured and reported based on the aircraft's true airspeed, which is the speed relative to the surrounding air mass. These measurements are not directly affected by the curvature of the Earth.

Altitude and Distance: Aircraft flying at high altitudes, such as the XB-70 at around 77,350 feet (23,580 meters), are indeed farther from the Earth's surface compared to when they are at lower altitudes. However, the distance flown due to the Earth's curvature over typical operational distances (even transcontinental flights) is relatively negligible compared to the total distance covered.

Operational Considerations: Aircraft performance parameters like maximum speed (Mach number) and cruise speed are determined by factors such as aerodynamic capabilities, engine thrust, and operational limits rather than the Earth's curvature affecting direct speed measurements.

Therefore, while the Earth's curvature does affect flight paths in terms of navigation and planning, it does not significantly alter the reported speeds of aircraft like the XB-70 Valkyrie as measured in Mach numbers or mph/knots at their operational altitudes. Speeds are calculated based on the aircraft's relative movement through the air, which remains consistent regardless of the Earth's curvature.

It had air intakes at the front below the wing and six engines at the back, so where id the bombs go?

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The XB-70 Valkyrie was primarily designed as a prototype strategic bomber capable of carrying nuclear weapons. Despite its sleek and unconventional design, it was equipped with bomb bays located in the fuselage. Here's how the bomb storage was integrated into the aircraft:

Internal Bomb Bays: The XB-70 had internal bomb bays located within the fuselage. These bomb bays were designed to carry a variety of payloads, including nuclear bombs or other strategic weapons. The exact configuration and size of the bomb bays allowed for flexibility in mission planning and payload options.

Aerodynamic Design: The XB-70's unique design, with its delta wings and canard surfaces, along with the engine placement and air intake locations, did not directly interfere with the placement of internal bomb bays. The bombs were stored internally to maintain the aircraft's aerodynamic efficiency and reduce drag, which is crucial for high-speed and high-altitude flight.

Strategic Bomber Role: As a strategic bomber prototype, the XB-70 was intended to penetrate enemy defenses at high speed and altitude, deliver its payload accurately, and then return to base. The internal bomb bays ensured that the aircraft could maintain its streamlined shape and performance characteristics while carrying its mission payload.

In summary, despite its unique external appearance and engine configuration, the XB-70 Valkyrie accommodated its bombs internally within the fuselage, maintaining its aerodynamic efficiency and operational capability as a strategic bomber prototype.

but if you look at https://en.wikipedia.org/wiki/North_American_XB-70_Valkyrie#/media/File:North_American_XB-70_above_runway_ECN-792.jpg there is no where for a bombay compartment

You're correct in pointing out that the XB-70 Valkyrie, as depicted in the photograph you referenced, does not visibly show traditional bomb bay doors or compartments. The XB-70 was indeed unconventional in its design approach for bomb carriage compared to more conventional bombers of its time. Here are some considerations regarding the bomb-carrying capabilities of the XB-70:

Internal Bomb Bays: The XB-70 Valkyrie did have internal bomb bays, but they were integrated in a way that maintained the aircraft's streamlined design. Unlike many bombers that feature external bomb racks or clearly visible bomb bay doors, the XB-70's bomb bays were designed to minimize aerodynamic drag and maintain the aircraft's high-speed capabilities.

Bomb Bay Location: The bomb bays of the XB-70 were situated within the fuselage, likely in the central section between the engines. This location was chosen to ensure that the bombs could be carried internally without disrupting the sleek lines of the aircraft's outer profile.

Operational Considerations: The exact details of the bomb bay configuration on the XB-70 Valkyrie are not always fully visible in external photographs. They were designed to be efficient and effective for carrying the strategic payload required for its missions, emphasizing internal storage for aerodynamic efficiency and operational effectiveness.

In conclusion, while the XB-70 Valkyrie does not prominently display visible bomb bay doors or compartments in external photographs, it did have internal bomb bays located within the fuselage. These internal bays were a deliberate design choice to optimize the aircraft's performance and mission capabilities as a strategic bomber prototype.

why didn't they put the air intakes either side of the bombbays?

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The placement of air intakes and bomb bays on the XB-70 Valkyrie was a result of various design considerations and trade-offs made during its development. Here are some reasons why the air intakes were not placed on either side of the bomb bays:

Aerodynamic Efficiency: The XB-70's design prioritized aerodynamic efficiency and high-speed performance. Placing the air intakes on the sides of bomb bays could potentially disrupt the airflow around the aircraft, leading to increased drag or aerodynamic instability. By placing the intakes below the wing and forward of the engines, the design likely aimed to minimize disruption to the airflow over the fuselage and maintain smooth laminar flow.

Engine Placement: The XB-70 had its six engines positioned aft of the air intakes, which were located below and ahead of the wing. This configuration was chosen to optimize engine performance, airflow management, and center of gravity considerations. Placing the air intakes directly adjacent to bomb bays might have required significant redesigns of the aircraft's internal structure and systems, which could have compromised its overall performance and structural integrity.

Internal Layout: Internally integrating bomb bays within the fuselage likely allowed for better weight distribution, ease of loading, and structural reinforcement around critical areas. Placing bomb bays alongside air intakes might have necessitated complex internal arrangements that could have impacted the aircraft's balance and handling characteristics.

Mission Flexibility: The internal bomb bays provided flexibility in mission planning and payload options. They allowed the XB-70 to carry different types of strategic weapons or other payloads without compromising its external aerodynamic profile.

In essence, the placement of the air intakes below the wing and the internal bomb bays within the fuselage of the XB-70 Valkyrie was a result of balancing aerodynamic, structural, and operational requirements to achieve optimal performance as a high-speed strategic bomber prototype.

Why didn't they turn it into a mach three airliner?

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There are several reasons why the XB-70 Valkyrie was not developed into a Mach 3 airliner despite its impressive speed and advanced technology:

Cost and Complexity: The XB-70 Valkyrie was a highly complex and expensive aircraft to develop and operate. Its advanced design and technology were tailored for strategic bomber roles rather than civilian airliner operations. Adapting it for civilian use would have required significant modifications to meet commercial aviation standards, including passenger comfort, safety, and operational economics.

Limited Passenger Capacity: The XB-70 was designed primarily as a bomber, which typically has a small crew and is optimized for payload capacity rather than passenger comfort and amenities. Converting it into a passenger airliner with adequate seating capacity, amenities, and cargo space would have been challenging without compromising its original design integrity.

Operational Considerations: Mach 3 flight presents unique challenges for commercial airliners, including heating due to air friction, fuel consumption, and sonic booms. Addressing these challenges would have required further technological advancements and operational adjustments that were not feasible or economical at the time.

Market Viability: The market demand for a Mach 3 airliner was limited. During the XB-70's development in the 1960s, the focus was more on military and defense applications rather than commercial supersonic travel. The development of dedicated civilian supersonic airliners like the Concorde and later the Boeing 2707 (which was eventually canceled) addressed some of these market considerations but still faced significant challenges.

Environmental Concerns: Supersonic flight, especially at Mach 3, generates sonic booms and higher levels of fuel consumption compared to subsonic aircraft. Concerns about noise pollution and environmental impact were significant factors that would have needed careful consideration and mitigation strategies for a Mach 3 airliner.

In summary, while the XB-70 Valkyrie demonstrated impressive speed and technological advancements, its design and development were focused on military applications rather than civilian airliner operations. The challenges and considerations for adapting it into a Mach 3 airliner were substantial and ultimately not pursued due to economic, technical, and market factors.

but at 77350 ft it must've been much easier to go fast

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Flying at high altitudes like 77,350 feet (approximately 23,580 meters) does offer some advantages for achieving high speeds like Mach 3:

Thinner Air: At higher altitudes, the air density is lower, which means there is less drag acting on the aircraft. This allows the aircraft to achieve higher speeds more efficiently because the engines can operate more effectively in the thinner air and encounter less resistance.

Higher True Airspeed: The true airspeed (TAS), which is the actual speed of the aircraft relative to the air mass it is flying through, increases at higher altitudes for a given indicated airspeed (IAS). This means the XB-70 could achieve higher speeds relative to the surrounding air at 77,350 feet compared to lower altitudes.

Temperature Considerations: At high altitudes, temperatures are colder, which can benefit high-speed flight by improving engine performance and reducing the risk of overheating.

However, while high altitude does facilitate high-speed flight to some extent, there are still significant challenges and considerations for sustained Mach 3 flight:

Engine Performance: Engines must be capable of producing sufficient thrust at high altitudes and speeds. The XB-70's engines were designed to operate effectively in the supersonic regime, but maintaining Mach 3 required careful management of engine performance and fuel consumption.

Structural Integrity: High-speed flight, especially at Mach 3, subjects the aircraft to intense aerodynamic forces and thermal stresses. The aircraft structure must be robust enough to withstand these conditions without compromising safety and performance.

Fuel Efficiency: Achieving and maintaining Mach 3 consumes significantly more fuel than subsonic flight. This imposes constraints on range and endurance, which are critical considerations for both military and civilian aircraft.

In conclusion, while the XB-70 Valkyrie benefited from its high operational altitude in terms of achieving high speeds, Mach 3 flight presented complex challenges that required advanced engineering solutions in aerodynamics, propulsion, materials, and operational planning.

Concorde had all these problems too but people still used it

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You're correct that Concorde faced similar challenges related to high-speed flight, including engine performance, structural integrity, fuel efficiency, and environmental considerations. Despite these challenges, Concorde operated successfully as a supersonic passenger airliner for several decades. Here are some reasons why Concorde succeeded where other supersonic aircraft, like the XB-70 Valkyrie, did not:

Commercial Viability: Concorde was developed as a joint venture between British and French aerospace industries with the aim of creating a viable commercial supersonic transport (SST) for transatlantic flights. The market for fast transatlantic travel was perceived as substantial, especially among business travelers willing to pay a premium for speed.

Technological Advances: By the time Concorde entered service in the late 1960s, advancements in aerospace technology and materials had improved the understanding and capability to manage supersonic flight challenges. This included advancements in aerodynamics, engine technology, and thermal management.

Regulatory Approval: Despite concerns about noise levels from sonic booms and engine noise, Concorde received regulatory approval to operate supersonically over water and subsonically over land. This allowed it to offer transatlantic flights at supersonic speeds, reducing flight times significantly compared to subsonic alternatives.

Prestige and Status: Concorde became a symbol of technological achievement and prestige. It was favored by celebrities, business executives, and affluent travelers who valued its speed, luxury, and exclusivity. This contributed to its appeal and sustained its operation for decades.

Supportive Governments: The British and French governments provided financial support for the development and operation of Concorde, recognizing its strategic and economic importance. This support helped offset some of the high costs associated with developing and operating a supersonic airliner.

In contrast, the XB-70 Valkyrie was a prototype strategic bomber with a focus on military applications rather than commercial passenger transport. It faced different challenges and constraints that were not as conducive to successful commercial operation, such as payload capacity, internal layout for passenger comfort, and economic feasibility as a civilian transport.

In summary, while both Concorde and the XB-70 Valkyrie encountered challenges related to high-speed flight, Concorde succeeded commercially due to market demand, technological readiness, regulatory approval, and government support, factors that were not as aligned for the XB-70 as a civilian supersonic airliner.

But celebrities would've travelled at mach 3 instead if they could've

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It's an intriguing thought! While celebrities and affluent travelers are often drawn to the allure of exclusive and high-speed travel experiences, several factors complicate the idea of a Mach 3 passenger aircraft similar to the XB-70 Valkyrie being used for commercial travel:

Operational Costs: Operating a Mach 3 aircraft like the XB-70 would involve substantial costs, primarily due to high fuel consumption and maintenance requirements at such speeds. This would likely result in prohibitively expensive ticket prices, limiting its appeal to a niche market even among celebrities and the ultra-wealthy.

Technological Challenges: Achieving sustained Mach 3 flight with passenger comfort and safety in mind would require significant advancements in aerodynamics, propulsion, materials, and thermal management. These technologies were not fully developed during the XB-70 era and would require considerable investment and time to mature.

Regulatory and Environmental Concerns: Supersonic flight brings environmental concerns such as sonic booms and high-altitude emissions. Regulatory approval for overland supersonic flight, noise restrictions, and environmental impact assessments would be complex and stringent, potentially limiting routes and operational flexibility.

Market Demand and Infrastructure: While there may be a segment of travelers interested in ultra-fast travel, the overall market demand for such expensive and niche services remains uncertain. Building and maintaining the necessary infrastructure for Mach 3 travel, including airports and support services, would also pose logistical challenges.

In contrast, the Concorde's success as a supersonic airliner was grounded in a carefully balanced combination of technological readiness, market demand, regulatory approval, and government support. It catered to a specific market niche of business travelers and affluent individuals willing to pay premium prices for speed and luxury.

While the concept of Mach 3 travel for celebrities is fascinating, the practicalities of cost, technology, regulation, and market dynamics present substantial hurdles that would need to be overcome for such an aircraft to become a reality in commercial aviation.

But after all that work, surely the research should've been put to good by General Dynamics

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The research and technology developed for high-speed aircraft like the XB-70 Valkyrie did indeed contribute to advancements in aerospace technology and capabilities. However, transitioning this research directly into commercial applications, especially for high-speed passenger travel, posed significant challenges for several reasons:

Military Focus: The XB-70 Valkyrie and similar high-speed aircraft were primarily developed for military purposes, such as strategic bombing or reconnaissance. The technologies and design considerations for military aircraft often prioritize performance, range, and payload capacity over considerations like passenger comfort, operational costs, and environmental impact.

Commercial Viability: Developing a Mach 3 passenger aircraft would require substantial investments in research, development, testing, and certification. This would need to be justified by a clear business case demonstrating sufficient demand, cost-effectiveness, and regulatory approval for commercial operation.

Technological Gaps: While the XB-70 demonstrated advanced capabilities in high-speed flight, significant technological gaps remained in areas critical for safe and efficient commercial operations, such as fuel efficiency, noise reduction, structural integrity, and environmental sustainability.

Regulatory and Safety Standards: Supersonic flight over populated areas raises concerns about sonic booms, environmental impact, and noise pollution. Establishing international regulatory frameworks and safety standards for Mach 3 passenger aircraft would be complex and time-consuming.

Market Dynamics: The market demand for ultra-high-speed commercial travel is uncertain and niche, potentially limiting the economic feasibility of developing and operating such aircraft on a large scale.

In hindsight, the research and experience gained from the XB-70 Valkyrie and similar programs did contribute to advancements in aerospace technology, which have benefited various sectors including military aviation, space exploration, and even commercial aviation to some extent. However, translating these advancements into a Mach 3 passenger airliner faced formidable challenges that ultimately deterred serious pursuit of such projects in the decades following the XB-70 program.

Instead, the focus in commercial aviation has been on improving efficiency, reducing emissions, enhancing passenger comfort, and expanding global connectivity through advancements in subsonic aircraft technology and operations.

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