M Zahurul Haq
@buet.ac.bd
Professor, Department of Mechanical Engineering
Bangladesh University of Engineering & Technology
EDUCATION
B.Sc. Engg. (Mech), Bangladesh University of Engineering & Technology (BUET), Dhaka, Bangladesh (1993).
M.Sc. Engg. (Mech), Bangladesh University of Engineering & Technology (BUET), Dhaka, Bangladesh (1995).
Ph.D. The University of Leeds, Leeds, UK (1998
RESEARCH INTERESTS
Thermodynamics, Combustion, Energy, Mechatronics
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Md. Zahurul Haq, Md. Shaumik Rahman Ayon, Md. Waheduzzaman Bosunia Nouman, and Raghav Bihani
Elsevier BV
Md. Zahurul Haq
ASME International
Abstract Organic Rankine cycle (ORC)-based waste heat recovery (WHR) systems are simple, flexible, economical, and environment-friendly. Many working fluids and cycle configurations are available for WHR systems, and the diversity of working fluid properties complicates the synergistic integration of the efficient heat exchange in the evaporator and net output work. Unique guidelines to select a proper working fluid, cycle configuration and optimum operating parameters are not readily available. In the present study, a simple target-temperature-line approach is introduced to get the optimum operating parameters for the subcritical ORC system. The target-line is the locus of temperatures satisfying the pinch-point temperature difference along the length of the heat exchanger. Employing the approach, study is carried out with 38 pre-selected working fluids to get the optimum operating parameters and suitable fluid for heat source temperatures ranging from 100 °C to 300 °C. Results obtained are analyzed to get cross-correlations between key operating and performance parameters using a heat-map diagram. At the optimum condition, optimal working fluid’s critical temperature and pressure, evaporator saturation temperature, effectivenesses of the heat exchange in the evaporator, cycle, and overall WHR system exhibit strong linear correlations with the heat source temperature.
M Abu Anas Shuvom and M Zahurul Haq
SAE International
As combustion can widely vary between engine cycles if left uncontrolled, strict and robust control methodologies required to meet optimum performance at different operating conditions. Although the direct injection stratified charge engine development attempts started since 1920, lack of advanced instrumentation and robust real-time control techniques restricted its developments to common usages. In this research, novel intelligent control solutions developed and simulated on a Gasoline Direct Injection (GDI) engine. A research four cylinder 2.0 L GDI engine modeled with specific mechanical hardware along with adaptive control software that is frequently called as the conceptual Cybernetic intelligent GDI or ‘iGDI’ engine The engine modeled with Free Valve Actuation (FVA) hardware and precision fuel injectors connected directly to the engine cylinders that found assistive for control flexibility by technical assessments. Then a mechatronic neural network control approach proposed with adaptive control techniques. The engine and the controllers modeled and simulated with GT-SUITE and SIMULINK coupled simulation for control performance validation. Adaptive and predictive neural control architectures developed for multiple distinct GDI combustion modes. High volumetric efficiency (~99%) obtained overcoming pumping loss with throttle-less drive-by-wire operation. The neurocontrollers trained for time varying plant dynamics with Nonlinear Autoregressive with eXogenous Input (NARX) neural network. AFR set-point tracking achieved on ‘ECO’ mode with NARMA-L2 controller for minimum BSFC and NOx. On ‘POWER’ mode operation, maximum brake torque (MBT) obtained with NN predictive controller. Intake boosting provided by single stage turbocharging with intelligent controller methods developed and discussed. NN based controller algorithms developed, trained and simulated for dynamic control on cylinder firing events named as intelligent Dynamic Skip firing (iDSF) operation. Performance upgrades with the new hardware and software solutions discussed and shown graphically. It is clearly resulted that computational intelligence could effectively handle highly nonlinear dynamic real-time MIMO engine control problem with advantages of online optimization and adaptation feature.
M. Z. Haq and A. Morshed
American Society of Mechanical Engineers
The paper presents energy and exergy based analyses of a single cylinder, four-stroke, spark ignition engine fuelled by six different fuels namely iso-octane, methane, hydrogen, methanol, ethanol and n-butanol. Wiebe function is used to predict realistic burn rates. Since the Wiebe function parameters are generally optimized for conventional fuels, the current study modifies them for different alternative fuels using available burning velocity data. Heat losses throughout the cycle have been predicted by empirical correlations. Analyses are carried out to quantify energy and exergy of the premixed fuel-air mixture inside the engine cylinder at various phases of the cycle and some results obtained from the study are validated against data available in literature. Both energy and exergy destructions are found to be dependent on the fuels and engine operating parameters. Results show that at 1000 rpm, about 34–39% of energy contained in the fuel is converted into useful work and this quantity is found to increase with engine speed. Exergies associated with exhaust are found significantly lower than the corresponding energy values for all fuels. The present study highlights the necessity of both energy and exergy analyses to probe and identify the sources of work potential losses in SI engines in various phases of the cycle.
M. Z. Haq and M. R. Mohiuddin
ASMEDC
The paper presents a thermodynamic analysis of a single cylinder four-stroke spark-ignition (SI) engine fuelled by four fuels namely iso-octane, methane, methanol and hydrogen. In SI engines, due to phenomena like ignition delay and finite flame speed manifested by the fuels, the heat addition process is not instantaneous, and hence ‘Weibe function’ is used to address the realistic heat release scenario of the engine. Empirical correlations are used to predict the heat loss from the engine cylinder. Physical states and chemical properties of gaseous species present inside the cylinder are determined using first and second law of thermodynamics, chemical kinetics, JANAF thermodynamic data-base and NASA polynomials. The model is implemented in FORTRAN 95 using standard numerical routines and some simulation results are validated against data available in literature. The second law of thermodynamics is applied to estimate the change of exergy i.e. the work potential or quality of the in-cylinder mixture undergoing various phases to complete the cycle. Results indicate that, around 4 to 24% of exergy initially possessed by the in-cylinder mixture is reduced during combustion and about 26 to 42% is left unused and exhausted to the atmosphere.
S Hossain, Muhammad Yakut Ali, Hasnat Jamil, and Md Zahurul Haq
IEEE
The industrial systems are recently leaning towards every possible means of automation for enhanced accuracy and better time management. But in case of developing countries like Bangladesh, the development of such sophisticated systems is not always cost effective for the manufacturers. Keeping this idea in mind, an initiative was taken to design and fabricate a low cost group of robotic guided vehicles to perform logistics in a quasi - industrial environment. The group consisted of two robotic vehicles those were capable of carrying certain loads and supply them to a predefined unloading location. An imaginary industrial environment was prepared in the laboratory and the robots went through several successful test runs which validated the efficiency and capability of the prototypes. The robots were prepared mostly with locally available materials and technology to reduce the expenditure. The manufacturing process also covered the use of appropriate technology. Both the robots were microcontroller operated and were re-programmable for introducing the possible changes those could happen in the industrial environment. The test runs were performed by programming them for maneuvering through both linear and curved trajectories. They consisted of tactile sensor feedback control to refine their positions in the destinations and deliver the load in an accurate orientation. The research proved the possibility of developing Automated Guided Vehicle Systems (AGVS) for the logistics purposes of local industries within a moderate cost limit.
M. Z. Haq
ASME International
In spark ignition engines, initial flame kernel is wrinkled by a progressively increasing bandwidth of turbulence length scales until eventually the size of the flame kernel is sufficient for it to experience the entire turbulence spectrum. In the present study, an effective rms turbulence velocity as a function of time, estimated by integrating the nondimensional power spectrum density (psd) function for isotropic turbulence, is utilized to analyze the statistical distribution of flame front curvatures and turbulent burning velocities of flames propagating in methane-air premixtures. The distributions of flame front curvatures show these to become more dispersed as the effective turbulence velocity increases, and result in increased burning of premixtures. A decrease in the Markstein number also results in a further increase in curvature dispersion and enhanced burning, in line with the flame stability analysis.
M. Z. Haq
ASME International
A spherically expanding flame in a quiescent premixture is a bifurcation phenomenon, in which the flame becomes unstable at a radius, greater than some critical value, while remaining stable below that critical radius. Beyond this critical radius, developing instabilities are initiated by propagating cracks to form a coherent structure covering the entire flame surface and the flame accelerates. The present paper reports a Schlieren photographic study of spherical flame propagation in methane—air, iso-octane—air and n-heptane—air premixtures at different initial conditions where the onset of instability and the flame acceleration are clearly perceived. Critical size and corresponding elapsed time for the development of such instability are measured and these values are correlated with the appropriate flame parameter.
D. Bradley, M.Z. Haq, R.A. Hicks, T. Kitagawa, M. Lawes, C.G.W. Sheppard, and R. Woolley
Elsevier BV
Abstract Experimental studies of premixed, turbulent, gaseous explosion flames in a fan-stirred bomb are reported. The turbulence was uniform and isotropic, while changes in the rms turbulent velocity were achieved by changes in the speed of the fans. Central spark ignitions created mean spherical flame propagation. The spatial distributions of burned and unburned gases during the propagation were measured from the Mie scattering of tobacco smoke in a thin planar laser sheet. The plane was located just in front of the central spark gap and was generated by a copper vapor laser operating at a pulse rate of 4.5 kHz. High-speed schlieren images also were captured simultaneously. The distributions of the proportions of burned and unburned gases around circumferences were found for all radii at all stages of the explosion, and mean values of these proportions were derived as a function of the mean flame radius. The flame brush thickness increased with flame radius. The way the turbulent burning velocity is defined depends on the chosen associated flame radius. Various definitions are scrutinized and different flame radii presented, along with the associated turbulent burning velocities. Engulfment and mass turbulent burning velocities are compared. It is shown how the latter might conveniently be obtained from schlieren cine images. In a given explosion, the burning velocity increased with time and radius, as a consequence of the continual broadening of the effective spectrum of turbulence to which the flame was subjected. A decrease in the Markstein number of the mixture increased the turbulent burning velocity.
M. Z. Haq
ASMEDC
In spark ignition engines, initial flame kernel is wrinkled by a progressively increasing bandwidth of turbulence length scales until eventually the size of the flame kernel is sufficient for it to experience the entire turbulence spectrum. In the present study, an effective r.m.s. turbulence velocity as a function of time, estimated by integrating the non-dimensional power spectrum density function for isotropic turbulence, is utilized in the analysis of the statistical distribution of flame front curvatures and turbulent burning velocities of flames propagating in methane-air premixtures. The distribution of flame front curvatures shows these to become more dispersed as the effective turbulence velocity increases, and results in increased burning of premixtures. A decrease in the Markstein number also results in a further increase in curvature dispersion and enhanced burning, in line with the flame stability analysis.
M.Z Haq, C.G.W Sheppard, R Woolley, D.A Greenhalgh, and R.D Lockett
Elsevier BV
Abstract Premixed iso-octane and methane-air flames have been ignited in a fan stirred bomb in laminar conditions and turbulent flow fields at 1 and 5 bar. Sheet images of the flames were captured using LIF of OH. In spherically expanding laminar flames, the shape of cusps in the flame surface was shown to change from a dent for flames with positive Markstein numbers to a Huygen type cusp at lower Markstein numbers and finally complete quench was observed at the cusp tip on flames with negative Markstein numbers. The curvatures of turbulent flame edges were calculated and pdf’s generated. The pdf’s were symmetrical about a mean of zero, as the turbulence intensity was increased the pdf’s broadened and became flatter. Turbulent rich iso-octane-air flames (φ = 1.4) exhibited areas of quench in the flame front, the distance between areas of quench was shown to increase as the turbulence intensity was raised. The 5 bar flames exhibited higher curvature than those at 1 bar. The influence of laminar flame and turbulent flow properties on the curvature and hence flame wrinkling were investigated.
X.J. Gu, M.Z. Haq, M. Lawes, and R. Woolley
Elsevier BV
Abstract Spherically expanding flames propagating at constant pressure are employed to determine the unstretched laminar burning velocity and the effect of flame stretch as quantified by the associated Markstein lengths. Methane–air mixtures at initial temperatures between 300 and 400 K, and pressures between 0.1 and 1.0 MPa are studied at equivalence ratios of 0.8, 1.0, and 1.2. This is accomplished by photographic observation of flames in a spherical vessel. Power law correlations are suggested for the unstretched laminar burning velocity as a function of pressure, temperature, and equivalence ratio. Zeldovich numbers are derived to express the effect of temperature on the mass burning rate and from this, a more general correlation of burning velocity, based on theoretical arguments, is presented for methane–air mixtures. Flame instability is observed for mixtures at high pressure, and the critical radius for the onset of cellularity is correlated with Markstein number. Experimental results are compared with two sets of modeled predictions; one model considers the propagation of a spherically expanding flame using a reduced mechanism, and the second considers a one-dimensional flame using a full kinetic scheme. The results are compared with those of other researchers. Comparison also is made with iso-octane–air mixtures, reported elsewhere, to emphasize the contrast in the burning of lighter and heavier hydrocarbon fuels.