Edit in JSFiddle

 <script src="https://d3js.org/d3.v4.min.js" charset="utf-8"></script>
 <svg id="content" width="600" height="400"></svg>

var data_set = { 
		    children: [
                  {name:"aaa", val:58},
                  {name:"bbb", val:88},
                  {name:"ccc", val:48},
                  {name:"ddd", val:73},
                  {name:"eee", val:81},
                  {name:"fff", val:31}  ] } ;
                   
var width=600, height=300;
var bubble = d3.pack()
    .size([width, height])
    .padding(1.5) ;

var nodes = d3.hierarchy( data_set )
              .sum(function(d){ return d.val })
          ;

var bubble_data = bubble(nodes).descendants() ;

var no_root_bubble = bubble_data.filter( function(d){ return d.parent != null ;} ) ;

var max_val = d3.max(no_root_bubble, function(d){ return d.r ;});     
var min_val = d3.min(no_root_bubble, function(d){return d.r ; });

var color_scale = d3.scaleLinear()
		.domain( [min_val, max_val] )
    .range(d3.schemeCategory10 );
var font_scale = d3.scaleLinear()
		.domain([min_val, max_val])
    .range([9, 28]);
    
var bubbles = d3.select("#content")
    .selectAll(".bubble")
    .data(no_root_bubble)
    .enter()
    .append("g")
    .attr("class", "bubble")
    .attr("transform", function(d){ return "translate("+d.x+","+d.y+")" ;})
    ;

bubbles.append("circle")
    .attr("r", function(d){ return d.r })
    .style("fill", function(d,i){ 
    			return color_scale(d.r); 
      });                  
      ; 
bubbles.append("text")
		.attr("text-anchor", "middle")
    .attr("dominant-baseline", "central")
    .text(function(d){ return d.data.name ; })
    .style("font-size", function(d){ return font_scale(d.r) ; })
    ;