Chapter 29 Design Concept
Engineer Bai Jingtian continued to introduce the design concept of this copycat missile.
Since this cruise missile does not need to make large flight movements like ordinary aircraft, the design thrust-to-weight ratio is about 0.25, which means the maximum take-off weight of the missile is about 0 kg.
Of course, you can also choose a foreign model commercial machine with a higher thrust-to-weight ratio and a more expensive price.
The engine uses aviation kerosene,
The full-load fuel consumption is about 0.8 liters per minute. After actual testing, the information of foreign model enthusiasts was directly used. The maximum actual working time of the engine is about 1 hour. Based on this design, the fuel tank capacity in the missile is about 80 liters. Flight
The speed is 0 kilometers per hour.
This engine is produced in the United States or Denmark, and the price is less than 3,000 US dollars each. I heard that domestic manufacturers will also produce it, and the price is expected to be half of that of imported products.
Engine cost: 45,000 yuan.
Second: Aerodynamic shape of the projectile
Since the missile is not an airplane, there is no need to consider too much maneuvering flight. The shape of the missile body is as simple as possible: a cylindrical missile body + a head fairing are used to maintain high structural strength while saving the most materials.
It is conducive to the installation of internal equipment. The designed bullet diameter is 35 cm, the total length is 180 cm, and the internal volume is about 0.35 cubic meters.
A straight-up monoplane wing structure with ailerons is used. The purpose of using a straight-up monoplane wing is to simplify the design and manufacturing and at the same time provide a relatively large lift-to-drag ratio; the purpose of using ailerons is to facilitate maneuvering and control. This
It is commonly used when making models and is relatively mature).
The designed wingspan is 1.8 meters, the chord length is 0.5 meters, and the wing area is 0.725 square meters. The V-shaped composite tail structure is adopted because this structure has a good foundation in aircraft models, the handling and control are relatively mature, and the stability is relatively good. Therefore,
Two pieces of tail are used instead of the traditional three pieces, which serve as both rudder and attitude control.
There are two advantages: simplifying the structure and avoiding the influence of the airflow of the engine. The engine is symmetrically installed on both sides of the missile body, with the center positioned behind the center. The advantage is that you don’t have to worry about designing the intake duct and tail nozzle, and try to keep both sides
The distance between the two engines is conducive to engine heat dissipation and avoids heat interference on the guidance and steering gear in the missile.
The entire missile body is made of aluminum alloy keels, aluminum alloy profiles, and riveted structures. The skin is made of resin fiberglass or carbon fiber. The latter is much more expensive, but it is much lighter at the same strength.
The layout inside the cylindrical missile from front to back is: pitot tube, missile-borne computer cabin, sensor cabin, missile wing servo, throttle governor, fuel tank, warhead, and tail servo.
Materials used include:
1: 6 model servos, two for each wing and one for each tail. Unit price: 80 yuan, totaling 480 yuan.
2: One V-shaped tail proportional distributor, unit price: 140 yuan.
3: Two throttle proportional speed regulators, unit price: 100 yuan, total: 0 yuan.
4: Two oil pumps, using car wiper water pump, unit price: RMB, total 40 RMB.
5: Several aluminum alloy profiles, several skins, several hardware parts, various adhesives, sealants, paints, hardware parts, and several standard parts.
The projectile cost is less than 5,000 yuan.
Three: Guidance and control part.
In fact, this part of the design is the most interesting. The entire system consists of hardware and software parts. Let’s talk about the hardware part first.
The missile-borne computer is responsible for two aspects of work, one is guidance and the other is control. It adopts the design concept of a standard micro industrial computer. The port is an 8-bit ISA socket and even has an integrated display card and sound card, which is only the size of a
3-inch floppy disk, plus a 256m electronic disk and a da converter for controlling the steering gear, weighing no more than 1 kg.
The total price is about 5,000 yuan. The receiving board, 12 channels, ia card, weighs about 50 grams, including the antenna, which is 0 grams. The price in Chengdu is 600 yuan.
Terrain: Industrial miniature radio altimeter, vertical range of 300 meters, rs-232 output, weighing about 300 grams with probe. The price in Beijing is more than 00 yuan.
Inertia: Industrial miniature gyroscope, with magnetic compass, rs-232 output, weight about 0 grams, price in Beijing is more than 1,500 yuan.
The above equipment is all powered by 5v, and the total current is less than 30 amps, including the servo. Considering the total working time is 1 hour, a 1.25v45 is used, and a lithium battery pack for laptops is chosen for power supply. The cost can also be kept at 50 yuan.
under.
After listening to the introduction, Li Baoqiang was stunned. This was simply a copycat cruise missile, and it was so cheap. He was very interested: "The final price? What is it?"
Bai Jingtian proudly said: "Excluding research and development costs, the cost is 100,000 yuan. If mass production is carried out, the cost can be further reduced."
"The research and development costs must be taken into account. In this way, for external sales, the price will be increased by 200% to 300,000 yuan per piece. I think the market must be hot. It is only 50,000 US dollars. It is very cheap and will definitely be popular!"
Li Moyang rubbed his hands together excitedly, thinking about the land of Africa, uh, no, those war-torn third world countries around the world. There was a flood of orders, and his hands cramped when he counted the money.
When Bai Jingtian, Wang Xiaolong and several other key workers heard what Li Moyang said, they all became excited. Who would have thought that a copycat cruise missile tinkered by just a few people would have such a bright future? It was so unfair.
Li Baoqiang thought for a while and his eyes lit up: "Just do it! You have done a good job in cost control, but you don't have to be too petty. The ultimate goal of everything is combat effectiveness. What we want is not a fun model aircraft, but
It is a reliable weapon. We will test this cruise missile now."
Bai Jingtian nodded in agreement: "Any weapon is successful after thousands of failures. I can't guarantee that there will be no errors during the test."
"It doesn't matter, let's go and try it now. We won't install the warhead, just pretend we are playing with model airplanes." Li Baoqiang laughed boldly.
Wang Xiaolong felt a pity: "My kind of spike missile has no solid fuel and cannot be tested, alas~~~"
"There will be bread, don't worry, produce it first, and I'll find a way to solid fuel. If that doesn't work, export it first. It will be easier to get fuel overseas."
Chapter completed!