A. K. M. Mohiuddin

Knowledge base for the systematic design of wet cooling towers. Part I: Selection and tower characteristics

Abstract This paper describes part of the detailed methodology for the thermal design of wet, counterflow and crossflow types of mechanical and natural draught cooling towers. Starting with a brief introduction, an attempt is made here to present different steps of cooling tower design. The steps include: selection of a cooling tower; determination of tower characteristic ratio; computation of moist air properties; determination of the ratio of the water-to-air loading; integration procedure for the tower characteristic ratio. The design of a cooling tower needs the use of different logical decisions, empirical relations and assumptions. The choice of a proper tower and its proper design would increase its efficiency and help conserve energy.

Knowledge base for the systematic design of wet cooling towers. Part II: Fill and other design parameters

Abstract This paper describes the final part of the detailed methodology for the thermal design of wet, counterflow and crossflow types of mechanical and natural draught cooling towers. This part includes the following design steps: the fill or packing, total packed height and the number of decks, water and air loading, pressure drop across the packing, natural draught tower, fan design for a mechanical draught cooling tower, blowdown and make-up water rate, water distribution systems and drift eliminators. Different empirical relations and assumptions are used in this part of the design procedure.

Load Distribution for an Intelligent Air-cushion Track Vehicle Based on Optimal Power Consumption

This study incorporates the computation of load distribution for an intelligent air-cushion track vehicle (IACTV) based on optimal power consumption (PC). A novel design auto adjusting air-cushion system has been designed and developed to minimise the PC. Focusing on optimising total PC, three main issues were studied in this paper. First, a theoretical model is developed for optimising total PC of the vehicle and the effects of load distribution on total PC. Second, a fuzzy expert system (FES) is used to control the swamp tracked vehicles intelligent air cushion system and thus minimise the PC. Third, an artificial neural network (ANN) model has been developed which has been trained to predict the total PC for IACTV and to provide illustration how FES might play an important role in the prediction of PC of the vehicles intelligent air-cushion system.

Waste cooking oil transesterification: Influence of impeller type, temperature, speed and bottom clearance on FAME yield

Waste cooking oil (WCO) provides an alternative source of raw material for biodiesel production. The reaction is both kinetics and mass transfer limited. Industrial use of current laboratory result suffer from dimensional non-compatibility because of the difference in the production environment especially as different impeller result in different flow characteristic during chemical reaction. In this work the effect of impeller type on fatty acid methyl ester (FAME) production from WCO was studied. At an alcohol oil mole ratio of 6:1 and 1% catalyst (oil weight), the Taguchi method was used for the experimental design of the transesterification in a 2 L stirred reactor using Rushton and elephant ear impellers. An optimum yield FAME at 70°C, 650 rpm impeller speed and 30 mm impeller bottom clearance (IBC) for Rushton impeller and 70°C, 700 rpm impeller speed and 25 mm IBC for an elephant ear impeller was obtained between 89 to 94%. IBC and speed were observed to have the most significant effect on yield using the signal to noise (S/N) ratio for Rushton and elephant ear impeller. Peak yield time between 5 to 30 min was observed. Correlation between FAME yield, peak time and temperature was high (0.968). The optimum reactor setting was at temperature 70°C, impeller speed of 650 rpm and IBC of 30 mm for Rushton (unbaffled reactor) and temperature 70°C, impeller speed of 700 rpm and IBC of 25 mm for elephant ear (baffled reactor). Physical configuration affected FAME yield/time in this work. Key words: Waste cooking oil, transesterification, impeller, Taguchi, biodiesel.

Integrated mechanics of hybrid electrical air-cushion tracked vehicle for swamp peat

This paper presents an integrated mechanics for the design of hybrid electrical air-cushion tracked vehicle. The air-cushion of HETAV is protected with a novel-design air-cushion supporting system which can adjust automatically. A propeller is installed on the vehicle to develop additional thrust for overcoming the dragging motion resistance of the air-cushion system. The mean values of traction for the vehicle with propeller compared with no propeller increased 10.21% and 6.47% for the vehicle weight of 2.45 kN and 3.43 kN, respectively. Similarly, it was found that the mean values of vehicle’s motion resistance decreases 12.63% and 25.81% for the vehicle weight of 2.45 kN and 3.43 kN, respectively.

Mobility Investigation of a Designed and Developed Segmented Rubber Track Vehicle on Sepang Peat Terrain in Malaysia

Abstract The traction mechanics of a vehicle was developed based on the track-terrain interaction mechanism. The vehicle was tested on three different terrains: terrain I, terrain II, and terrain III. The tractive effort of the vehicle increased 14 per cent when the moisture content of the terrain increased from 59.85 per cent to 81.06 per cent. A traction coefficient of 48 per cent of the vehicles gross weight justified the vehicles optimum design for the Sepang peat terrain. Less variability of the vehicles tractive effort for straight motion in the range of 7.5 per cent to 13.2 per cent and for turning motion in the range of 9 per cent to 11.5 per cent between the predicted and measured tractive effort on the peat terrain III for different loading and operating speeds substantiate the validity of the developed mathematical model.

Nonlinear controller of an air-cushion system for a swamp terrain vehicle: fuzzy logic approach

This paper presents the fuzzy logic controller (FLC) of an air-cushion system for a swamp peat terrain vehicle and describes the process by which it functions. Cushion pressure is controlled by an electronic proportional control valve and FLC using the output signal of the distance (height) measuring sensor that was attached to the vehicle. The main purpose of this study was to develop a control scheme for an air-cushion system and to investigate the relationship between vehicle vertical position and the air-cushion system, and to illustrate the important role of the fuzzy logic control system. Experimental values were recorded in the laboratory for control system testing, and in the swamp peat terrain field for vehicle performance investigation. In this paper, a fuzzy logic expert system (FLES) model, based on the Mamdani approach, was developed to predict the changes in flowrate. The mean relative error of actual and predicted values from the FLES model of flowrate was found to be slightly above the acceptable limit. The goodness of fit of the prediction values from the FLES model was found to be close to 1.0 as expected, and hence demonstrated the good performance of the developed system.

A study on automated traction control system of an electrical golf car

This study presents an automated traction control system (ATCS) without incorporating the function of hydraulic system. The ATCS is used for improving the vehicle performance in terms of stability and torque or speed needed in order to produce smooth driving. Driving motor and wheel speed sensor (WSS) with RPM meter are used in this study to develop the sufficient torque or speed on demand of the driving wheel. The current flow is controlled to the driving motor with the help of electronic proportional valve. A slope sensor is used in the proposed system to enhance the power supply to the driving motor when the vehicle will be in the grade of 10%-20%. SolidWorks simulation and laboratory experiment has been performed to investigate the performance of the designed and developed automated traction control system on the dry and slippery surface.

Application of Multi-Objective Genetic Algorithm (MOGA) for Design Optimization of Valve Timing at Various Engine Speeds

This paper aims to demonstrate the effectiveness of Multi-Objective Genetic Algorithm Optimization and its practical application on the automobile engine valve timing where the variation of performance parameters required for finest tuning to obtain the optimal engine performances. The primary concern is to acquire the clear picture of the implementation of Multi-Objective Genetic Algorithm and the essential of variable valve timing effects on the engine performances in various engine speeds. Majority of the research works in this project were in CAE software environment and method to implement optimization to 1D engine simulation. The paper conducts robust design optimization of CAMPRO 1.6L (S4PH) engine valve timing at various engine speeds using multiobjective genetic algorithm (MOGA) for the future variable valve timing (VVT) system research and development. This paper involves engine modelling in 1D software simulation environment, GT-Power. The GT-Power model is run simultaneously with mode Frontier to perform multiobjective optimization.

ESTOWER: An expert system for the thermal design of wet cooling towers

Abstract An expert system based on logic programming has been developed, using a systematic procedure for the thermal design of natural and mechanical draft wet cooling towers of the counterflow and crossflow types. The present system is based on a rule-based system. The “VIDHI”, expert-system shell written in LISP, has been used as a tool to develop the present system. The “VIDHI” shell is based on backward chaining. The inference mechanism of the system is similar to that of PROLOG. The rule set of the expert system was developed by using a tree structure for the entire design process. Besides designing a cooling tower for a given situation, the expert system can also be used for teaching and learning about cooling-tower design.