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Ravikiran et al.
1 Introduction
A sounding rocket is a small rocket capable of performing scientific and research
experiments at altitudes well below the orbit [1, 2]. Model rockets are small prototypes of sounding rocket commonly made of wood, plastic and other lightweight
materials. Regardless of the use of highly flammable substances and high travel
speeds, the model rocketry still stands as a safe amusement and a great source of
inspiration for infants and young scientists. Model rockets which combine different
fields from aerodynamic design to pyrotechnics to the model building were difficult
to be manufactured early [3]. Rapid technological advancements had outpaced this
and presently these rockets are affordable as well as safe to fabricate. Model and
high-power rockets are designed for safe recovery and repeated flight. To aid this,
several methods are adopted, the most common of which is the use of parachute and
streamer [4, 5]. A parachute recovery system is annexed to the nose of the rocket and
is triggered by the ejection charge of the engine. This ensures the safe retrieval of the
rocket motor [6]. This paper aims to understand the underlying principle of model
rocketry. The primary objective of this work is to design and develop a cost-effective
reloadable motor with a reusable nozzle for an experimental sounding rocket [7]. The
nozzle which is a functional part of the rocket was carefully designed to generate
the necessary thrust load for lift. The pressure, temperature and velocity distribution
within the nozzle are evaluated through computational analysis using ANSYS fluent.
2 Materials and Methods
2.1 Solid Propellent
The solid propellant used in this study was a mixture of Potassium Nitrate (KNO 3 )
and sugar hereby referred to as KNSu taken in a ratio of 13:7. Prior to mixing, the
powdered KNO 3 was baked in an oven for 20 min at a temperature of 250 °C in
order to remove the moisture content. The method of dry compression was adopted
for the preparation of propellent [5]. Initially, 35 g of fine sugar powder and 65 g
of pre-heated finely ground Potassium Nitrate were carefully mixed by hand in a
closed container to avoid self-ignition. The resultant white mix was then rammed
into the aluminium motor with the help of a rubber mallet. Following this, a layer
of bentonite clay was rammed to keep the fuel intact and a hole was drilled in it to
allow for the expansion of fuel.
Ravikiran et al.
1 Introduction
A sounding rocket is a small rocket capable of performing scientific and research
experiments at altitudes well below the orbit [1, 2]. Model rockets are small prototypes of sounding rocket commonly made of wood, plastic and other lightweight
materials. Regardless of the use of highly flammable substances and high travel
speeds, the model rocketry still stands as a safe amusement and a great source of
inspiration for infants and young scientists. Model rockets which combine different
fields from aerodynamic design to pyrotechnics to the model building were difficult
to be manufactured early [3]. Rapid technological advancements had outpaced this
and presently these rockets are affordable as well as safe to fabricate. Model and
high-power rockets are designed for safe recovery and repeated flight. To aid this,
several methods are adopted, the most common of which is the use of parachute and
streamer [4, 5]. A parachute recovery system is annexed to the nose of the rocket and
is triggered by the ejection charge of the engine. This ensures the safe retrieval of the
rocket motor [6]. This paper aims to understand the underlying principle of model
rocketry. The primary objective of this work is to design and develop a cost-effective
reloadable motor with a reusable nozzle for an experimental sounding rocket [7]. The
nozzle which is a functional part of the rocket was carefully designed to generate
the necessary thrust load for lift. The pressure, temperature and velocity distribution
within the nozzle are evaluated through computational analysis using ANSYS fluent.
2 Materials and Methods
2.1 Solid Propellent
The solid propellant used in this study was a mixture of Potassium Nitrate (KNO 3 )
and sugar hereby referred to as KNSu taken in a ratio of 13:7. Prior to mixing, the
powdered KNO 3 was baked in an oven for 20 min at a temperature of 250 °C in
order to remove the moisture content. The method of dry compression was adopted
for the preparation of propellent [5]. Initially, 35 g of fine sugar powder and 65 g
of pre-heated finely ground Potassium Nitrate were carefully mixed by hand in a
closed container to avoid self-ignition. The resultant white mix was then rammed
into the aluminium motor with the help of a rubber mallet. Following this, a layer
of bentonite clay was rammed to keep the fuel intact and a hole was drilled in it to
allow for the expansion of fuel.