2. RADIAL ENGINE
The radial engine is a reciprocating type internal combustion engine configuration in which the
cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a
stylized star when viewed from the front, and is called a "star engine" in some other languages.
Since the axes of the cylinders are coplanar, the connecting rods cannot all be directly attached to the
crankshaft unless mechanically complex forked connecting rods are used, none of which have been
successful. Instead, the pistons are connected to the crankshaft with a master-and-articulating-rod
assembly. One piston, the uppermost one in the animation, has a master rod with a direct attachment to
the crankshaft. The remaining pistons pin their connecting rods' attachments to rings around the edge of
the master rod. Extra "rows" of radial cylinders can be added in order to increase the capacity of the engine
without adding to its diameter.
3. SCOPE OF THE PROJECT
Radial engines are a type of internal combustion engine that have a unique design and
arrangement of cylinders. Here are some key scopes and aspects related to radial engines:
Design and Configuration :
·Radial engines have a circular arrangement of cylinders
that radiate outwards from a central crankshaft.
·The cylinders are typically arranged in odd numbers,
such as 3, 5, 7, or 9, although some historical engines
had even numbers.
·The crankshaft is fixed, and the cylinders are attached
to it through a master rod and individual connecting
Engine Operation :
·Radial engines operate on the principle of
reciprocating motion, where the pistons move
back and forth within the cylinders.
·The radial configuration allows for a simpler
crankcase design and provides good cooling
due to the exposed cylinder heads.
·The crankshaft rotates with the propeller, and
the pistons are connected to the crankshaft
via the connecting rods.
·Fuel and air mixture is ignited in each
cylinder, generating power and producing the
characteristic radial engine sound.
·Radial engines were widely used in aviation during
the early and mid-20th century. They powered
various aircraft, including fighters, bombers, and
·They were renowned for their reliability, high
torque, and ability to operate at low speeds.
·Radial engines were also utilized in stationary
applications such as power generation, pumping
stations, and industrial machinery.
4 Advantages :
·Radial engines have excellent reliability due to
their simple design and fewer moving parts
compared to other engine configurations.
·They provide high torque output, making them
suitable for applications that require substantial
power at low rotational speeds.
·Radial engines have good cooling characteristics
because the rotating motion creates airflow
around the cylinders.
5 Disadvantages :
·While radial engines are no longer prevalent in aviation,
they are still used in certain vintage aircraft, as well as in
restoration and hobbyist projects.
·Radial engine designs continue to inspire new
developments in engine technology, particularly in the field
of power generation and alternative energy systems.
5. DESIGNING THE PROJECT
SPECIFYING THE WORK PLANE/
The next step is to create a 2-
dimensional profile of the part. The
Sketcher Work Bench is a two-
dimensional (planar) work area. To
use the Sketcher Work Bench, you
must specify which plane the profile
is to be created on. Specifying, the
plane can be done several different
Specifying the Work Plane
SKETCHING AND DESIGNING THE PARTS/
1. The sketch for the
required shape (circle) is
drawn using required tools
in the tool bar. Two circles
of diameters 2 4 m m and
15mm respectively drawn
and the sketch is
constrained by placing it at
a distance of 8 9 m m to the
left of vertical plane.
Sketch 1 of Sh aft
7. 2. Then the sketch is extruded using the pad tool to a length of 14mm using the pad
Pad 1 of Sh aft
8. 3. Again two concentric circles are drawn using required tools in the tool bar. Two circles of diameters
24mm and 35mm respectively are drawn and the sketch is constrained by placing it at a distance of
89mm to the right of vertical plane.
Sketch 2 of Shaft
9. 4. The newly drawn sketch is extruded using the pad tool to a length of 21mm using the
Pad 2 of Shaft
10. 5. A profile of height 18mm is drawn and constrained connecting the two padded concentric
circles using the profile command.
Sketch 3 of Shaft
11. 6. The newly drawn sketch is extruded using the pad tool to a length of 9 m m using
the pad command.
Pad 3 of Shaft
12. 7. A profile of height 10mm and length 130mm is drawn on the upper surface of the
recently padded sketch using the profile command.
Sketch 4 of Shaft
13. 8. A pocket for a depth of 6.5mm is made for the profile that is drawn using the pocket
Pocket 1 of Sh aft
14. 9. The pocket created is mirrored on the other side of the x-y plane with the help of the
M irror 1 of Sh aft
15. 10. Edge fillets are created for a radius of 24mm using the edge fillet command.
Ed ge Fillet 1 of Sh aft
16. 11. The profile is sketched using the tools in the tool bar as shown in the figure.
Sketch 5 of Shaft
17. 12. The drawn profile is padded to the required length using the pad command as
shown in the figure.
Pad 4 of Shaft
18. 13. The part is designed successfully using the sketching tools and designing tools and saved.
19. Similarly, the other parts of the radial engine are drawn, constrained and
OTHER PARTS OF RADIAL ENGINE
Master Bearing Rod
22. /ASSEMBLY OF THE DESIGNED PARTS/
The individual parts which are designed using the CATIA is assembled by
opening the Assembly Design Tab in drop down tab of Mechanical design
option in start button. Then the designed individual components are needed to
be imported to the Assembly Design tab for assembly which can be done by
clicking Existing Component icon in Product Structure Tools, it is shown in the
23. Then the assembly of the imported parts can be performed by using the
respective Assembly constraints such as
The first step in assembly is to fix any one of the imported component so that
we can attain the desired assembly in short period of time. Here the component
Main Rod is fixed and the other parts are aligned with the help of assembly
The design of a radial engine offers a combination of simplicity, reliability, and
power. Its circular arrangement of cylinders around a central crankshaft allows for a
c o m p a c t design and efficient cooling. While it may be larger and heavier than other
engine types, its smooth operation and high torque output ma ke it suitable for
applications that require strong performance, particularly in aviation. Overall, the
radial engine's enduring design continues to be valued for its robustness and ability
to deliver reliable power.
Overall, radial engines have played a significant role in aviation and industrial
applications, offering reliable and powerful performance, and they continue to hold a
special place in the history and development of internal combustion engines.