Papers by Harijono Djojodihardjo
United Nations Programme on Space Applications, 2000
Acta Astronautica, Mar 1, 2015
The Proceedings of the ... International Offshore and Polar Engineering Conference, 1993
A simple method to solve potential flow problems of submerged body-surface wave interaction is pr... more A simple method to solve potential flow problems of submerged body-surface wave interaction is presented. The Laplace equation governs flow below the surface. The boundary condition on the body is of Neumann type, while on the free surface the nonlinear dynamic free surface condition has to be satisfied. In addition, the farfield and radiation condition, which determine the behaviour of waves going to infinity, have to be satisfied. Taking advantage of the potential flow model, Green Identity is then used to transform the problem of the Laplace equation with nonlinear boundary conation into a nonlinear problem in its boundary. To satisfy the nonlinear dynamic free surface condition, Newton iteration is employed. The scheme for relaxation is obtained by expanding the nonlinear dynamic free surface condition to obtain correction terms to the velocity potential. Truncation up to linear terms results in a simple scheme. Since the dynamic condition is valid on the unknown location of the free surface, in each iteration step the position of the free surface where the equation is applied, is corrected using the Bernoulli equation. In this manner, dynamic free surface condition is satisfied exactly at the collocation points. Results from two and three dimensional nonlifting problem are presented as examples.
DOAJ (DOAJ: Directory of Open Access Journals), Feb 1, 2019
The analytical approach to buffeting problem in subsonic flow is a challenging one and has been g... more The analytical approach to buffeting problem in subsonic flow is a challenging one and has been given attention by many researchers; no purely analytical approach has been satisfactorily capable of simulating the phenomenon. An attempt to develop a computational method for the calculation of the aerodynamic load for separated subsonic flow using kernel function technique in linearized aerodynamics has been made by the author and his associates, as an alternative to the more accurate but elaborate technique of direct numerical attack to the viscous flow problem. Two approaches were then made. First, to treat the buffeting problem as a stability one by solving the flutter equation. Second, treating buffeting problem using dynamic response approach. Comparison of the unsteady load calculation method with other existing results for non-separated flow cases indicated good agreements. For separated flow case, no other methods are available for comparison. However, flutter solution approach made by the present study indicated that the presence of the separation bubble tends to destabilize the system compared to the attached flow case. The analytical approach to the buffeting problem using dynamic response technique was made by assuming that there is no coupling between the motion induced unsteady loads and the independent-motion unsteady loads. The motion induced unsteady airloads is calculated using the present method while the buffeting excitation load was based on experimental data. Computational results for the bending moment of a wing experiencing buffeting with experimental results indicated good agreement but lower values for the onset of buffeting.
IAF abstracts, 34th COSPAR Scientific Assembly, 2002
and economic progress, while facing global competitiveness locally as opportunities and challenge... more and economic progress, while facing global competitiveness locally as opportunities and challenges. Of particular importance is the utilization and development of earth observation capabilities for environmental natural resources imperatives to this end is quite significant. On one hand there may appear challenges to achieve unique and high quality requirements on many of the elements of social and economic progress, i.e.
Journal of Material Sciences & Engineering, Mar 28, 2016
Advances in Astronautics Science and Technology, Nov 21, 2018
DOAJ (DOAJ: Directory of Open Access Journals), Feb 1, 2019
The governing equation of transonic small disturbance flow present a non-linear partial different... more The governing equation of transonic small disturbance flow present a non-linear partial differential equation which is difficult to solve. The method of parametric differentiation reduces the non-linear partial differential equation of transonic flow into an ordinary differential equation with variable coefficient, which is generally much simple to solve. Further simplification is introduced, as also done in the method of local linearization, by assuming (1-M 1 2 ) to vary sufficiently slowly, so that in some part of the analysis its derivatives with respect to x can be disregarded. Based upon these methods, the lifting transonic flow was analyzed. For the subsonic and supersonic parts, closed form solutions were obtained. For the case M 1 ≈ 1, the method yields an integral equation, which can be solved by an iterative scheme starting from the non-lifting solution.
Advances in civil and industrial engineering book series, 2017
Springer eBooks, 1995
A brief survey of the kernel functions occurring in unsteady subsonic or supersonic lifting surfa... more A brief survey of the kernel functions occurring in unsteady subsonic or supersonic lifting surface formulations is presented. The discussion will be focused on the solutions of the improper cylindrical function as a main part of the kernel function. A new expansion series is proposed as an exact solution to the improper integral and may be regarded as an extension of the Ueda series. The new solution offers a very simple and convenient form since the singular and regular parts are explicitly separated. The simple form of the singular functions is a key point which is particularly significant in simplifying the Mangler integration; hence this approach is shown to be useful in improving the accuracy of many planar and nonplanar lifting surface methods. Results are discussed and their accuracy is presented.
DEStech Transactions on Environment, Energy and Earth Science, Jan 10, 2017
Advanced Science Letters, Feb 1, 2014
Journal of Medical Imaging and Health Informatics, Oct 1, 2016
Based on the authors’ various studies on Coandă effect, the present study is devoted to focus on ... more Based on the authors’ various studies on Coandă effect, the present study is devoted to focus on the development and influence of Coandă effect on the flow along a conduit with constriction representing the upper respiratory system of the human body, including the constriction dynamics and aerodynamics that may prevail there. For this purpose, theoretical analyses as well as CFD simulation are being carried out. Comparison of the results obtained with other medical based studies has exhibited striking similarities and are assessed for their physical significance.
Publication of: Society of Automotive Engineers, 1987
An analysis of lateral and directional steady state stability of a typical small commercial vehic... more An analysis of lateral and directional steady state stability of a typical small commercial vehicle configuration is performed limiting the movement to three degrees of freedom: side slipping, yawing and rolling. Based on the analysis, a parametric study is performed to investigate the influence of some design and operational parameters, in order to arrive at some design guidelines. SAE paper no 871182. (Author/TRRL)
Journal of mechanics engineering and automation, Apr 28, 2013
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Papers by Harijono Djojodihardjo
Masalah penggunaan sumber daya nuklir pada wahana antariksa telah menark perhatian banyak negara di dunia, berkaitan dengan keprihatinan terhadap kejatuhan pecahan satelit yang bersifat radio aktif. Untuk memahami lingkup bahaya yang mungkin timbul, akan dibahas aspek penggunaan sumber daya nuklir pada wahana antariksa.
Abstract
The issue of nuclear power source in space vehile has drawn concern of many countries for the possibility of their space debris during failure or decommissionimng and other related nuclear contamination that may affect the earth environment. To this end and to gain further knowledge on this issue, various aspects on the use of nuclear power in spacecrafts to date are elaborated.
It is with such motivation that within the aerodynamics surface blowing techniques, and Coandă jet will be reviewed, to assess their characteristics in dramatically alter the behavior of aerodynamic components such as airfoils, wings, and bodies. Capitalizing on a host of research and technology development efforts on Coandă and surface blowing circulation enhancement, the present work reviews the influence, effectiveness and configuration of airfoil surface blowing of Coandă-jet in circulation enhancement and control of aerodynamic surfaces and their applications to MAV’s dynamics and related technologies. The crux of the Coandă jet active research is their stabilization and contol, which will be relevant in its application to Coanada MAV’s.
Based on an exhaustive review on Offshore Wind Energy and Photo Voltaic Power System technology and Applications in various parts of the world, and particular applications in Malaysia and Indonesia, a comprehensive insight on the potential and prospects of wind and photovoltaic energy, two promising renewable energies, are elaborated. An example of a conceptual design and preliminary configuration of a Co-Located Photovoltaic Agriculture system is proposed, including the probable investment and rate of return.
Insinyur Professional Utama (IPU, Perhimpunan Insinyur Indonesia),
ASEAN Chartered Professional Engineer (ACPE, ASEAN Chartered Professional Engineer Coordinating Committee)
Academician, International Academy of Astronautics,
Senior Life Member, American Institute of Aeronautics and Astronautics
Chairman of the Board
Yayasan Persada Kriyareka Dirgantara (The Institute for the Advancement of Aerospace Science and Technology)
Jakarta 15419, Indonesia
Founding Member and Advisor, Pusat Kajian Teknologi dan Inovasi – Center for Technology and Innovation Studies
E-mail: [email protected];[email protected]; [email protected]; [email protected]; [email protected]
author to have an introspection and retrospection of what the
author has experienced during his life, that is when his 80th
birthday forthcoming. It is also intended to be an expression to
God Almighty that has endowed upon him a life that the
author has been extremely gratified. Then, what should be
written should be something that the author has learned and
like to share with his children, grandchildren, relatives,
students and former students alike, and more importantly to
the interested readers and mankind. It is by no means an
autobiography or memoir, but something like a part of a “flashback”, that may represent
my “accountability” in life. Having spent a large part of my life in academia, as a civil
servant in government institutions dealing with science and technology, and partly in
industry, but realizing that no extraordinary achievement have been delivered to the
public, it seems appropriate that I would start from how and why what I have been doing
began. It appears to me that all of these started from “my dream”, and from what I have
been thankful, my capability to use my “reasoning capability”. This is something that
need more thoughtful elaboration, and this is all about the book. My dream and why I
have dreamed. I just want to share this dream and how I have been attempting to
realize this dream through a life paradigm that I dubbed “Being Together” reflecting the
high-values of mankind reflected by many, if not all religions, that is Love, Care, Share,
Give and Serve. In my mother’s tongue Javanese, this is expressed as “Guyub: Tresno,
Gumati, Asih-Asih-Asuh, Caos, Laden”. I cannot claim I have delivered many downstream
products to mankind and universe, but I have a dream and started to interact
with mankind and nature from upstream and from within my deep-self, by using the
most sacred gift from God-All-Mighty, my “reasoning capability”, with the objective to
contribute to the development of the culture of the society that should be so based,
though my expertise. The latter goes on the scientific attitude and scientific culture, to
expansion and sharing with associates the dream to generate the following dreams. As
cases in point, writings and presentations, are ways of expressing your dream to a certain
extent, disseminating ideas, and interact with co-workers, mostly young and inspiring
young colleagues. These I found gratifying.
With such background, the book is intended by the author to contribute in the
long run to the cultural development and transformation of the nation, along the line of
the historical progress of mankind, for the development of the nation to acquire smart
and competitive culture. And that dictates the title of the book INGENUITY FOR
NATIONAL CULTURE. Starting from basic philosophical point of views, motivation and
ideas are elaborated. The product of the dream and reasoning capabilities that have
been enjoyed by the author are exemplified in other dreams: presentations and
scientific work in partnership with co-workers that represent development efforts, which
could still comprise further scientifically elaborated dreams. For the author, the choice of
the title of the book is natural and intuitional.
At the beginning of the writing, the book contains chapters in Indonesia and
English, following the relevant event presented. Constructive suggestions by reviewers
lead to the split up of the book into two versions. One, a shorter version in Indonesian,
and another one, a most complete delivery of the ideas in English. The present one is
the latter. In elaborating the ideas following the dream and motivation, the chapters are
divided into two groups, Macro-Aspects and Micro-Aspects.
As a closing remark, the author would like to thank many individuals that have
given constructive suggestions to the preliminary edition of the book. Likewise, the
author would welcome further suggestions and criticism from the readers for mutual
interest.
The main objective of the work, based on resorting to a simple approach but the capability to provide a quick impression on the physical phenomena being studied, and limitation in time and hardware resources that prevail in an educational environment,
subject to instructional objectives for participating students, is to devise an approach for gaining insight and carry out numerical computation and simulation approach based on first principles, aerodynamic and flight mechanic modeling, and on linearized approach. The approach can be further modified with certain relationships to account for the difference with physically observed phenomena using either approximation or analytically derived relationships obtained by leading researchers,
or by heuristically derived approximations based on analytical work, physical reasoning and experiments, and Computational Fluid Dynamic simulations.
With such background, the book is intended by the author to contribute in the long run to the cultural development and transformation of the nation, along the line of the historical progress of mankind, for the development of the nation to acquire smart and competitive culture. And that dictates the title of the book INGENUITY FOR NATIONAL CULTURE. Starting from basic philosophical point of views, motivation and ideas are elaborated. The product of the dream and reasoning capabilities that have been enjoyed by the author are exemplified in other dreams: presentations and scientific work in partnership with co-workers that represent development efforts, which could still comprise further scientifically elaborated dreams. For the author, the choice of the title of the book is natural and intuitional.
To complement the ideas elaborated in the chapters, the author provides a detailed biography. Having completed his engineering education at the Institute of Technology of Bandung (ITB), University of Kentucky and Massachusetts Institute of Technology (MIT) , he has served as academic faculty member at ITB and other universities, at the Government Science and Technology Offices such as The Indonesian Space Agency (LAPAN), the Agency for the Assessment and Application of Technology (BPPT), The Indonesia Aircraft Industry (PT IPTN, now PT DI) and the Office of the President, among others. These experiences have strengthened his motivation and dedication to contribute pro-actively for the cultural development of his Nation, at his capacity as a member of the silent moral force.
At the beginning of the writing, the book contains chapters in Indonesia and English, following the relevant event presented. Constructive suggestions by reviewers lead to the split up of the book into two versions. One, a shorter version in Indonesian, and another one, a most complete delivery of the ideas in English. The present one is the latter. In elaborating the ideas following the dream and motivation, the chapters are divided into two groups, Macro-Aspects and Micro-Aspects.
The biography of the author is elaborated in some detail en-lieu of elaborating it in the main text to provide further background for the essays contained in the main body of the book.
As a closing remark, the author would like to thank many individuals that have given constructive suggestions to the preliminary edition of the book. Likewise, the author would welcome further suggestions and criticism from the readers for mutual interest.
Through a priori meticulous assumptions and sound application of first principles, the approach should be capable to reveal pertinent features of the physical phenomena to a logical and acceptable extent. A posteriori assessment of such approach would judge the extent of its applicability. Such approach involves approximations since the true flight system is so complicated which may not be tractable using first principles in their simple forms. However, when the analysis is confined to free flight and make use of the most reliable flight data available, the task will be more manageable, since it is possible to introduce simple corrections.
Then the objectives and contributions of this work are (i) To present and asses a simple approach which are based on first principles, translated into in house computational programs that should be capable of revealing particular characteristics, for conceptual design tool and establishing a simple and workable model. (ii) To review and establish a baseline of the state of the art based on the wealth of literature to date as check points. (iii) To summarize some critical and relevant characteristics, and identify which of these could be tackled with a simple approach, and which
cannot. (iv) To assess the usefulness and limitations of the approach, which will be useful for further elaborate approach.
INTRODUCTION:
2.
RENEWABE ENERGY POTENTIAL
3.
WORLD ENERGY LANDSCAPE
4.
PROGRESS AND RECENT TRENDS OF
RENEWABLE ENERGY TECHNOLOGY
5.
THE POTENTIAL AND IMPLEMENTATION OF
RENEWABLE ENERGY DEVELOPMENT IN
INDONESIA
6.
GLOBAL AND INDONESIAN SOLAR IRRADIATION
7.
GLOBAL WIND ENERGY POTENTIAL
8.
PHOTOVOLTAIC SOLAR ENERGY UTILIZATION IN
INDONESIA
9.
EXAMPLES OF SOLAR HOME SYSTEM
10.
WIND ENERGY TECHNOLOGY OVERVIEW
11.
STRATEGIC FEATURES OF WIND ENERGY
TECHNLOGY
12.
SOLAR PHOTOVOLTAIC Examples
13.
ECONOMICS OVERVIEW
14.
BRIEF ANALYSIS AND PROSPECTS
15.
CONCLUDING REMARKS
16.
THE WAY FORWARD