Space systems design (spacecraft, satellites, space stations and their equipment)
Sajjad Gharezi; Mohammad Mehdi Doustdar
Articles in Press, Accepted Manuscript, Available Online from 17 January 2024
Abstract
In this research, the design of a can combustion chamber for a ramjet engine, the performance of this chamber and the role of flameholder have been studied. For this purpose, after talking about ramjet engine types, some general information about the combustion chamber has been explained. Then the process ...
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In this research, the design of a can combustion chamber for a ramjet engine, the performance of this chamber and the role of flameholder have been studied. For this purpose, after talking about ramjet engine types, some general information about the combustion chamber has been explained. Then the process of chamber designing and determining its geometry has been discussed. The dimensions of the chamber were determined by using input conditions extracted from GasTurb software as well as applying a calculation code, and the geometry of the chamber have been determined by applying calculation codes. By evaluating the obtained geometry and ensuring the accuracy of the design, simulation of combustion with non-premixed liquid phase was carried out using Fluent software. While presenting the results, the effects of size, distance and number of flameholder have been investigated. It is shown that the use of flameholder in ramjet engines is essential but the use of large flameholder is not recommended.
Mohammad Moumivand; hasan mohammadkhani; javad heydari; mohammad hosein vaezi
Volume 10, Issue 2 , September 2017, , Pages 65-72
Abstract
Determining aerodynamic coefficients and control and stability derivatives play animportant role in the development of flight vehicles. In this paper, roll damping coefficientof BASIC FINNER standard model is determined at different attack angles and withvarious Mach numbers using numerical Sliding Mesh ...
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Determining aerodynamic coefficients and control and stability derivatives play animportant role in the development of flight vehicles. In this paper, roll damping coefficientof BASIC FINNER standard model is determined at different attack angles and withvarious Mach numbers using numerical Sliding Mesh method. Also, the impact of theeffective parameters such as amplitude and frequency of oscillation, time step and numberof iteration in each step in numerical solution are investigated to determine the rolldamping coefficients. Geometry modeling and grid generation and the flow analysis aredone by ANSYS CFX and ANSYS FLUENT software, respectively. In this simulation,Euler’s flow equations, compressible and unsteady flow, finite volume method and densitybased solver with explicit formulation and first-order accuracy for a numerical solutionare used. To evaluate the results of a numerical study, a comparison is made between theexperimental data and MD results, indicating that the results have a good accuracy.
Amir Mahdi Tahsini; Samaneh Tadayon Mousavi
Volume 8, Issue 4 , January 2016, , Pages 29-34
Abstract
The aim of this paper is to identify the unknown properties of an industrial hot air gun using inverse heat transfer approach. A combination of experiments and numerical analyses is used to define the convection coefficient and the produced temperature of this device. A numerical solver is developed ...
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The aim of this paper is to identify the unknown properties of an industrial hot air gun using inverse heat transfer approach. A combination of experiments and numerical analyses is used to define the convection coefficient and the produced temperature of this device. A numerical solver is developed by employment of a straightforward and powerful inverse heat transfer method: “The conjugate gradient method for parameter estimation”. The variation of temperature versus time in a fixed point of a steel-304 rod is sensed by a thermocouple and is given as an input to the numerical solver. The produced temperature of the hot air gun and the variation of convection heat transfer coefficient of this device as a function of distance between gun and rod are estimated in this research. Two non-dimensional distances between hot air gun and head of rod, H/D, are considered in this research: 2 and 6. These distances are chosen based on the hot jet potential core, the former is inside the potential core and the latter is outside it. The identifications of this gun are used in the process of determining unknown thermal properties of insulating and ablative materials, which are essential components of ablative heat shields, by inverse heat transfer methods.
